Date & Time

LocalTime Introduction

When building scheduling applications, alarm systems, or tracking business hours, you need to work with time independently of dates. LocalTime handles clock time operations with nanosecond precision.

LocalTime represents a time without date in the ISO calendar system (hour-minute-second-nanosecond). It's part of the java.time package introduced in Java 8.

Getting Current Time

Current.java
Replay: real traced execution (multi-file project)
// Current time

import java.time.LocalTime;

public class Current {

    public static void main(String[] args) {
        // Static replay uses a fixed sample "now".
        LocalTime now = LocalTime.of(14, 30, 45, 123456789);
        System.out.println("Sample now: " + now);

        // Time components
        int hour = now.getHour();
        int minute = now.getMinute();
        int second = now.getSecond();
        int nano = now.getNano();

        System.out.println("\nTime components:");
        System.out.println("Hour: " + hour);
        System.out.println("Minute: " + minute);
        System.out.println("Second: " + second);
        System.out.println("Nanosecond: " + nano);

        // Formatted output
        System.out.println("\nFormatted:");
        System.out.println(String.format("%02d:%02d:%02d", hour, minute, second));

        // 12-hour format
        int hour12 = hour % 12;
        if (hour12 == 0) hour12 = 12;
        String amPm = hour < 12 ? "AM" : "PM";
        System.out.println(String.format("%02d:%02d %s", hour12, minute, amPm));

        // Truncated times
        LocalTime toMinute = now.withSecond(0).withNano(0);
        System.out.println("\nTruncated to minute: " + toMinute);

        LocalTime toSecond = now.withNano(0);
        System.out.println("Truncated to second: " + toSecond);

        // Special times
        LocalTime midnight = LocalTime.MIDNIGHT;
        LocalTime noon = LocalTime.NOON;
        LocalTime min = LocalTime.MIN;
        LocalTime max = LocalTime.MAX;

        System.out.println("\nSpecial times:");
        System.out.println("Midnight: " + midnight);
        System.out.println("Noon: " + noon);
        System.out.println("Min: " + min);
        System.out.println("Max: " + max);

        // Seconds of day
        int secondOfDay = now.toSecondOfDay();
        System.out.println("\nSecond of day: " + secondOfDay);
        System.out.println("Total seconds in day: " + (24 * 60 * 60));
    }

}

  1. now ← 14:30:45.123456789, hour ← 14, minute ← 30, second ← 45

    7public static void main(String[] args) {8    // Static replay uses a fixed sample "now".9    LocalTime now→ 14:30:45.123456789 = LocalTime.of(14, 30, 45, 123456789);10    System.out.println("Sample now: " + now14:30:45.123456789);1112    // Time components13    int hour→ 14 = now.getHour();14    int minute→ 30 = now.getMinute();15    int second→ 45 = now.getSecond();16    int nano→ 123456789 = now.getNano();1718    System.out.println("\nTime components:");19    System.out.println("Hour: " + hour14);20    System.out.println("Minute: " + minute30);21    System.out.println("Second: " + second45);22    System.out.println("Nanosecond: " + nano123456789);2324    // Formatted output25    System.out.println("\nFormatted:");26    System.out.println(String.format("%02d:%02d:%02d", hour14, minute30, second45));2728    // 12-hour format29    int hour12→ 2 = hour14 % 12;30    if (hour12 == 0) hour12 = 12;31    String amPm→ PM = hour14 < 12 ? "AM" : "PM";32    System.out.println(String.format("%02d:%02d %s", hour122, minute30, amPmPM));3334    // Truncated times35    LocalTime toMinute→ 14:30 = now.withSecond(0).withNano(0);36    System.out.println("\nTruncated to minute: " + toMinute14:30);3738    LocalTime toSecond→ 14:30:45 = now.withNano(0);39    System.out.println("Truncated to second: " + toSecond14:30:45);4041    // Special times42    LocalTime midnight→ 00:00 = LocalTime.MIDNIGHT;43    LocalTime noon→ 12:00 = LocalTime.NOON;44    LocalTime min→ 00:00 = LocalTime.MIN;45    LocalTime max→ 23:59:59.999999999 = LocalTime.MAX;4647    System.out.println("\nSpecial times:");48    System.out.println("Midnight: " + midnight00:00);49    System.out.println("Noon: " + noon12:00);50    System.out.println("Min: " + min00:00);51    System.out.println("Max: " + max23:59:59.999999999);5253    // Seconds of day54    int secondOfDay→ 52245 = now.toSecondOfDay();55    System.out.println("\nSecond of day: " + secondOfDay52245);56    System.out.println("Total seconds in day: " + (24 * 60 * 60));57}
    outputSample now: 14:30:45.123456789

Time components:
Hour: 14
Minute: 30
Second: 45
Nanosecond: 123456789

Formatted:
14:30:45
02:30 PM

Truncated to minute: 14:30
Truncated to second: 14:30:45

Special times:
Midnight: 00:00
Noon: 12:00
Min: 00:00
Max: 23:59:59.999999999

Second of day: 52245
Total seconds in day: 86400
LocalTime An immutable time object representing hour, minute, second, and nanosecond without date or timezone information.

Creating Specific Times

time1
Create.java
Replay: real traced execution (multi-file project)
// Create specific time

import java.time.LocalTime;

public class Create {

    public static void main(String[] args) {
        // Create with hour and minute
        LocalTime time1 = LocalTime.of(14, 30);
        System.out.println("Time 1 (HH:MM): " + time1);

        // Create with hour, minute, second
        LocalTime time2 = LocalTime.of(14, 30, 45);
        System.out.println("Time 2 (HH:MM:SS): " + time2);

        // Create with hour, minute, second, nanosecond
        LocalTime time3 = LocalTime.of(14, 30, 45, 123456789);
        System.out.println("Time 3 (with nanos): " + time3);

        // Common times
        LocalTime morning = LocalTime.of(9, 0);
        LocalTime lunchTime = LocalTime.of(12, 30);
        LocalTime evening = LocalTime.of(18, 0);

        System.out.println("\nCommon times:");
        System.out.println("Morning: " + morning);
        System.out.println("Lunch: " + lunchTime);
        System.out.println("Evening: " + evening);

        // Midnight and noon
        LocalTime midnight = LocalTime.MIDNIGHT;  // 00:00
        LocalTime noon = LocalTime.NOON;          // 12:00

        System.out.println("\nSpecial:");
        System.out.println("Midnight: " + midnight);
        System.out.println("Noon: " + noon);

        // Modify components
        LocalTime modified = time1.withHour(16).withMinute(45);
        System.out.println("\nModified: " + modified);

        // Create from second of day
        int secondOfDay = 12 * 60 * 60 + 30 * 60;  // 12:30
        LocalTime fromSeconds = LocalTime.ofSecondOfDay(secondOfDay);
        System.out.println("From seconds (12:30): " + fromSeconds);

        // Create from nanosecond of day
        long nanoOfDay = 12L * 60 * 60 * 1_000_000_000 + 30L * 60 * 1_000_000_000;
        LocalTime fromNanos = LocalTime.ofNanoOfDay(nanoOfDay);
        System.out.println("From nanos (12:30): " + fromNanos);

        // Min and max
        LocalTime min = LocalTime.MIN;
        LocalTime max = LocalTime.MAX;
        System.out.println("\nMin: " + min);
        System.out.println("Max: " + max);

        // Generate hourly times
        System.out.println("\nHourly times:");
        for (int hour = 9; hour <= 17; hour++) {
            LocalTime t = LocalTime.of(hour, 0);
            System.out.println("  " + t);
        }
    }

}

// Create specific time

import java.time.LocalTime;

public class Create {

    public static void main(String[] args) {
        // Create with hour and minute
        LocalTime time1 = LocalTime.of(9, 15);
        System.out.println("Time 1 (HH:MM): " + time1);

        // Create with hour, minute, second
        LocalTime time2 = LocalTime.of(14, 30, 45);
        System.out.println("Time 2 (HH:MM:SS): " + time2);

        // Create with hour, minute, second, nanosecond
        LocalTime time3 = LocalTime.of(14, 30, 45, 123456789);
        System.out.println("Time 3 (with nanos): " + time3);

        // Common times
        LocalTime morning = LocalTime.of(9, 0);
        LocalTime lunchTime = LocalTime.of(12, 30);
        LocalTime evening = LocalTime.of(18, 0);

        System.out.println("\nCommon times:");
        System.out.println("Morning: " + morning);
        System.out.println("Lunch: " + lunchTime);
        System.out.println("Evening: " + evening);

        // Midnight and noon
        LocalTime midnight = LocalTime.MIDNIGHT;  // 00:00
        LocalTime noon = LocalTime.NOON;          // 12:00

        System.out.println("\nSpecial:");
        System.out.println("Midnight: " + midnight);
        System.out.println("Noon: " + noon);

        // Modify components
        LocalTime modified = time1.withHour(16).withMinute(45);
        System.out.println("\nModified: " + modified);

        // Create from second of day
        int secondOfDay = 12 * 60 * 60 + 30 * 60;  // 12:30
        LocalTime fromSeconds = LocalTime.ofSecondOfDay(secondOfDay);
        System.out.println("From seconds (12:30): " + fromSeconds);

        // Create from nanosecond of day
        long nanoOfDay = 12L * 60 * 60 * 1_000_000_000 + 30L * 60 * 1_000_000_000;
        LocalTime fromNanos = LocalTime.ofNanoOfDay(nanoOfDay);
        System.out.println("From nanos (12:30): " + fromNanos);

        // Min and max
        LocalTime min = LocalTime.MIN;
        LocalTime max = LocalTime.MAX;
        System.out.println("\nMin: " + min);
        System.out.println("Max: " + max);

        // Generate hourly times
        System.out.println("\nHourly times:");
        for (int hour = 9; hour <= 17; hour++) {
            LocalTime t = LocalTime.of(hour, 0);
            System.out.println("  " + t);
        }
    }

}

  1. time1 ← 14:30, time2 ← 14:30:45, time3 ← 14:30:45.123456789, morning ← 09:00

    7public static void main(String[] args) {8    // Create with hour and minute9    LocalTime time1→ 14:30 = LocalTime.of(14, 30); //@time1=LocalTime.of(14, 30), LocalTime.of(9, 15)10    System.out.println("Time 1 (HH:MM): " + time114:30);1112    // Create with hour, minute, second13    LocalTime time2→ 14:30:45 = LocalTime.of(14, 30, 45);14    System.out.println("Time 2 (HH:MM:SS): " + time214:30:45);1516    // Create with hour, minute, second, nanosecond17    LocalTime time3→ 14:30:45.123456789 = LocalTime.of(14, 30, 45, 123456789);18    System.out.println("Time 3 (with nanos): " + time314:30:45.123456789);1920    // Common times21    LocalTime morning→ 09:00 = LocalTime.of(9, 0);22    LocalTime lunchTime→ 12:30 = LocalTime.of(12, 30);23    LocalTime evening→ 18:00 = LocalTime.of(18, 0);24    25    System.out.println("\nCommon times:");26    System.out.println("Morning: " + morning09:00);27    System.out.println("Lunch: " + lunchTime12:30);28    System.out.println("Evening: " + evening18:00);2930    // Midnight and noon31    LocalTime midnight→ 00:00 = LocalTime.MIDNIGHT;  // 00:0032    LocalTime noon→ 12:00 = LocalTime.NOON;          // 12:0033    34    System.out.println("\nSpecial:");35    System.out.println("Midnight: " + midnight00:00);36    System.out.println("Noon: " + noon12:00);3738    // Modify components39    LocalTime modified→ 16:45 = time1.withHour(16).withMinute(45);40    System.out.println("\nModified: " + modified16:45);4142    // Create from second of day43    int secondOfDay→ 45000 = 12 * 60 * 60 + 30 * 60;  // 12:3044    LocalTime fromSeconds→ 12:30 = LocalTime.ofSecondOfDay(secondOfDay45000);45    System.out.println("From seconds (12:30): " + fromSeconds12:30);4647    // Create from nanosecond of day48    long nanoOfDay→ 45000000000000 = 12L * 60 * 60 * 1_000_000_000 + 30L * 60 * 1_000_000_000;49    LocalTime fromNanos→ 12:30 = LocalTime.ofNanoOfDay(nanoOfDay45000000000000);50    System.out.println("From nanos (12:30): " + fromNanos12:30);5152    // Min and max53    LocalTime min→ 00:00 = LocalTime.MIN;54    LocalTime max→ 23:59:59.999999999 = LocalTime.MAX;55    System.out.println("\nMin: " + min00:00);56    System.out.println("Max: " + max23:59:59.999999999);5758    // Generate hourly times59    System.out.println("\nHourly times:");60    for (int hour = 9; hour <= 17; hour++) {
    outputTime 1 (HH:MM): 14:30
Time 2 (HH:MM:SS): 14:30:45
Time 3 (with nanos): 14:30:45.123456789

Common times:
Morning: 09:00
Lunch: 12:30
Evening: 18:00

Special:
Midnight: 00:00
Noon: 12:00

Modified: 16:45
From seconds (12:30): 12:30
From nanos (12:30): 12:30

Min: 00:00
Max: 23:59:59.999999999

Hourly times:

  2. t ← 09:00

    pass 1 of 9
    59System.out.println("\nHourly times:");60for (int hour9 = 9; hour <= 17; hour++) {61    LocalTime t→ 09:00 = LocalTime.of(hour9, 0);62    System.out.println("  " + t09:00);63}
    output  09:00
    All 9 passes — pass 1 is the card above
    passhourt
    1909:00
    21010:00
    31111:00
    41212:00
    51313:00
    61414:00
    71515:00
    81616:00
    91717:00

  1. time1 ← 09:15, time2 ← 14:30:45, time3 ← 14:30:45.123456789, morning ← 09:00

    7public static void main(String[] args) {8    // Create with hour and minute9    LocalTime time1→ 09:15 = LocalTime.of(9, 15);10    System.out.println("Time 1 (HH:MM): " + time109:15);1112    // Create with hour, minute, second13    LocalTime time2→ 14:30:45 = LocalTime.of(14, 30, 45);14    System.out.println("Time 2 (HH:MM:SS): " + time214:30:45);1516    // Create with hour, minute, second, nanosecond17    LocalTime time3→ 14:30:45.123456789 = LocalTime.of(14, 30, 45, 123456789);18    System.out.println("Time 3 (with nanos): " + time314:30:45.123456789);1920    // Common times21    LocalTime morning→ 09:00 = LocalTime.of(9, 0);22    LocalTime lunchTime→ 12:30 = LocalTime.of(12, 30);23    LocalTime evening→ 18:00 = LocalTime.of(18, 0);24    25    System.out.println("\nCommon times:");26    System.out.println("Morning: " + morning09:00);27    System.out.println("Lunch: " + lunchTime12:30);28    System.out.println("Evening: " + evening18:00);2930    // Midnight and noon31    LocalTime midnight→ 00:00 = LocalTime.MIDNIGHT;  // 00:0032    LocalTime noon→ 12:00 = LocalTime.NOON;          // 12:0033    34    System.out.println("\nSpecial:");35    System.out.println("Midnight: " + midnight00:00);36    System.out.println("Noon: " + noon12:00);3738    // Modify components39    LocalTime modified→ 16:45 = time1.withHour(16).withMinute(45);40    System.out.println("\nModified: " + modified16:45);4142    // Create from second of day43    int secondOfDay→ 45000 = 12 * 60 * 60 + 30 * 60;  // 12:3044    LocalTime fromSeconds→ 12:30 = LocalTime.ofSecondOfDay(secondOfDay45000);45    System.out.println("From seconds (12:30): " + fromSeconds12:30);4647    // Create from nanosecond of day48    long nanoOfDay→ 45000000000000 = 12L * 60 * 60 * 1_000_000_000 + 30L * 60 * 1_000_000_000;49    LocalTime fromNanos→ 12:30 = LocalTime.ofNanoOfDay(nanoOfDay45000000000000);50    System.out.println("From nanos (12:30): " + fromNanos12:30);5152    // Min and max53    LocalTime min→ 00:00 = LocalTime.MIN;54    LocalTime max→ 23:59:59.999999999 = LocalTime.MAX;55    System.out.println("\nMin: " + min00:00);56    System.out.println("Max: " + max23:59:59.999999999);5758    // Generate hourly times59    System.out.println("\nHourly times:");60    for (int hour = 9; hour <= 17; hour++) {
    outputTime 1 (HH:MM): 09:15
Time 2 (HH:MM:SS): 14:30:45
Time 3 (with nanos): 14:30:45.123456789

Common times:
Morning: 09:00
Lunch: 12:30
Evening: 18:00

Special:
Midnight: 00:00
Noon: 12:00

Modified: 16:45
From seconds (12:30): 12:30
From nanos (12:30): 12:30

Min: 00:00
Max: 23:59:59.999999999

Hourly times:

  2. t ← 09:00

    pass 1 of 9
    59System.out.println("\nHourly times:");60for (int hour9 = 9; hour <= 17; hour++) {61    LocalTime t→ 09:00 = LocalTime.of(hour9, 0);62    System.out.println("  " + t09:00);63}
    output  09:00
    All 9 passes — pass 1 is the card above
    passhourt
    1909:00
    21010:00
    31111:00
    41212:00
    51313:00
    61414:00
    71515:00
    81616:00
    91717:00

Time Components

time
Components.java
Replay: real traced execution (multi-file project)
// Time components

import java.time.LocalTime;

public class Components {

    public static void main(String[] args) {
        LocalTime time = LocalTime.of(14, 30, 45, 123456789);

        System.out.println("Time: " + time);
        System.out.println();

        // Hour, minute, second
        System.out.println("Hour: " + time.getHour());
        System.out.println("Minute: " + time.getMinute());
        System.out.println("Second: " + time.getSecond());
        System.out.println("Nanosecond: " + time.getNano());

        // Convert to seconds of day
        int secondOfDay = time.toSecondOfDay();
        System.out.println("\nSecond of day: " + secondOfDay);

        // Convert to nanoseconds of day
        long nanoOfDay = time.toNanoOfDay();
        System.out.println("Nano of day: " + nanoOfDay);

        // Calculate milliseconds component
        int millis = time.getNano() / 1_000_000;
        System.out.println("\nMilliseconds: " + millis);

        // 12-hour format components
        int hour24 = time.getHour();
        int hour12 = hour24 % 12;
        if (hour12 == 0) hour12 = 12;
        String amPm = hour24 < 12 ? "AM" : "PM";

        System.out.println("\n12-hour format:");
        System.out.println("Hour (12): " + hour12);
        System.out.println("AM/PM: " + amPm);
        System.out.println("Time: " + String.format("%d:%02d %s",
            hour12, time.getMinute(), amPm));

        // Truncate precision
        LocalTime toMinute = time.withSecond(0).withNano(0);
        LocalTime toSecond = time.withNano(0);

        System.out.println("\nTruncated:");
        System.out.println("Original: " + time);
        System.out.println("To minute: " + toMinute);
        System.out.println("To second: " + toSecond);

        // Check if before/after noon
        System.out.println("\nIs before noon: " + time.isBefore(LocalTime.NOON));
        System.out.println("Is after noon: " + time.isAfter(LocalTime.NOON));

        // Time periods
        System.out.println("\nTime period:");
        if (time.getHour() < 12) {
            System.out.println("Morning");
        } else if (time.getHour() < 17) {
            System.out.println("Afternoon");
        } else if (time.getHour() < 21) {
            System.out.println("Evening");
        } else {
            System.out.println("Night");
        }

        // Display various times
        System.out.println("\nVarious times of day:");
        LocalTime[] times = {
            LocalTime.of(6, 0),
            LocalTime.of(12, 0),
            LocalTime.of(18, 0),
            LocalTime.of(23, 59)
        };

        for (LocalTime t : times) {
            System.out.println(t + " - " + t.getHour() + "h " +
                             t.getMinute() + "m");
        }
    }

}

// Time components

import java.time.LocalTime;

public class Components {

    public static void main(String[] args) {
        LocalTime time = LocalTime.of(9, 5, 0);

        System.out.println("Time: " + time);
        System.out.println();

        // Hour, minute, second
        System.out.println("Hour: " + time.getHour());
        System.out.println("Minute: " + time.getMinute());
        System.out.println("Second: " + time.getSecond());
        System.out.println("Nanosecond: " + time.getNano());

        // Convert to seconds of day
        int secondOfDay = time.toSecondOfDay();
        System.out.println("\nSecond of day: " + secondOfDay);

        // Convert to nanoseconds of day
        long nanoOfDay = time.toNanoOfDay();
        System.out.println("Nano of day: " + nanoOfDay);

        // Calculate milliseconds component
        int millis = time.getNano() / 1_000_000;
        System.out.println("\nMilliseconds: " + millis);

        // 12-hour format components
        int hour24 = time.getHour();
        int hour12 = hour24 % 12;
        if (hour12 == 0) hour12 = 12;
        String amPm = hour24 < 12 ? "AM" : "PM";

        System.out.println("\n12-hour format:");
        System.out.println("Hour (12): " + hour12);
        System.out.println("AM/PM: " + amPm);
        System.out.println("Time: " + String.format("%d:%02d %s",
            hour12, time.getMinute(), amPm));

        // Truncate precision
        LocalTime toMinute = time.withSecond(0).withNano(0);
        LocalTime toSecond = time.withNano(0);

        System.out.println("\nTruncated:");
        System.out.println("Original: " + time);
        System.out.println("To minute: " + toMinute);
        System.out.println("To second: " + toSecond);

        // Check if before/after noon
        System.out.println("\nIs before noon: " + time.isBefore(LocalTime.NOON));
        System.out.println("Is after noon: " + time.isAfter(LocalTime.NOON));

        // Time periods
        System.out.println("\nTime period:");
        if (time.getHour() < 12) {
            System.out.println("Morning");
        } else if (time.getHour() < 17) {
            System.out.println("Afternoon");
        } else if (time.getHour() < 21) {
            System.out.println("Evening");
        } else {
            System.out.println("Night");
        }

        // Display various times
        System.out.println("\nVarious times of day:");
        LocalTime[] times = {
            LocalTime.of(6, 0),
            LocalTime.of(12, 0),
            LocalTime.of(18, 0),
            LocalTime.of(23, 59)
        };

        for (LocalTime t : times) {
            System.out.println(t + " - " + t.getHour() + "h " +
                             t.getMinute() + "m");
        }
    }

}

  1. time ← 14:30:45.123456789, secondOfDay ← 52245, nanoOfDay ← 52245123456789

    7public static void main(String[] args) {8    LocalTime time→ 14:30:45.123456789 = LocalTime.of(14, 30, 45, 123456789); //@time=LocalTime.of(14, 30, 45, 123456789), LocalTime.of(9, 5, 0)9    10    System.out.println("Time: " + time14:30:45.123456789);11    System.out.println();1213    // Hour, minute, second14    System.out.println("Hour: " + time.getHour());15    System.out.println("Minute: " + time.getMinute());16    System.out.println("Second: " + time.getSecond());17    System.out.println("Nanosecond: " + time.getNano());1819    // Convert to seconds of day20    int secondOfDay→ 52245 = time.toSecondOfDay();21    System.out.println("\nSecond of day: " + secondOfDay52245);2223    // Convert to nanoseconds of day24    long nanoOfDay→ 52245123456789 = time.toNanoOfDay();25    System.out.println("Nano of day: " + nanoOfDay52245123456789);2627    // Calculate milliseconds component28    int millis→ 123 = time.getNano() / 1_000_000;29    System.out.println("\nMilliseconds: " + millis123);3031    // 12-hour format components32    int hour24→ 14 = time.getHour();33    int hour12→ 2 = hour2414 % 12;34    if (hour12 == 0) hour12 = 12;35    String amPm→ PM = hour2414 < 12 ? "AM" : "PM";36    37    System.out.println("\n12-hour format:");38    System.out.println("Hour (12): " + hour122);39    System.out.println("AM/PM: " + amPmPM);40    System.out.println("Time: " + String.format("%d:%02d %s", 41        hour122, time.getMinute(), amPmPM));4243    // Truncate precision44    LocalTime toMinute→ 14:30 = time.withSecond(0).withNano(0);45    LocalTime toSecond→ 14:30:45 = time.withNano(0);46    47    System.out.println("\nTruncated:");48    System.out.println("Original: " + time14:30:45.123456789);49    System.out.println("To minute: " + toMinute14:30);50    System.out.println("To second: " + toSecond14:30:45);5152    // Check if before/after noon53    System.out.println("\nIs before noon: " + time.isBefore(LocalTime.NOON));54    System.out.println("Is after noon: " + time.isAfter(LocalTime.NOON));5556    // Time periods57    System.out.println("\nTime period:");58    if (time.getHour() < 12) {
    outputTime: 14:30:45.123456789
Hour: 14
Minute: 30
Second: 45
Nanosecond: 123456789

Second of day: 52245
Nano of day: 52245123456789

Milliseconds: 123

12-hour format:
Hour (12): 2
AM/PM: PM
Time: 2:30 PM

Truncated:
Original: 14:30:45.123456789
To minute: 14:30
To second: 14:30:45

Is before noon: false
Is after noon: true

Time period:

  2. if (time.getHour() < 17)

    59    System.out.println("Morning");60} else if (time.getHour() < 17) {61    System.out.println("Afternoon");62} else if (time.getHour() < 21) {
    outputAfternoon

  3. LocalTime[] times =

    68// Display various times69System.out.println("\nVarious times of day:");70LocalTime[] times = {71    LocalTime.of(6, 0),72    LocalTime.of(12, 0),73    LocalTime.of(18, 0),74    LocalTime.of(23, 59)75};
    output
Various times of day:

  4. for (LocalTime t : times)

    pass 1 of 4
    77for (LocalTime t06:00 : times) {78    System.out.println(t06:00 + " - " + t.getHour() + "h " + 79                     t.getMinute() + "m");80}
    output06:00 - 6h 0m
    All 4 passes — pass 1 is the card above
    passt
    106:00
    212:00
    318:00
    423:59

  1. time ← 09:05, secondOfDay ← 32700, nanoOfDay ← 32700000000000

    7public static void main(String[] args) {8    LocalTime time→ 09:05 = LocalTime.of(9, 5, 0);9    10    System.out.println("Time: " + time09:05);11    System.out.println();1213    // Hour, minute, second14    System.out.println("Hour: " + time.getHour());15    System.out.println("Minute: " + time.getMinute());16    System.out.println("Second: " + time.getSecond());17    System.out.println("Nanosecond: " + time.getNano());1819    // Convert to seconds of day20    int secondOfDay→ 32700 = time.toSecondOfDay();21    System.out.println("\nSecond of day: " + secondOfDay32700);2223    // Convert to nanoseconds of day24    long nanoOfDay→ 32700000000000 = time.toNanoOfDay();25    System.out.println("Nano of day: " + nanoOfDay32700000000000);2627    // Calculate milliseconds component28    int millis→ 0 = time.getNano() / 1_000_000;29    System.out.println("\nMilliseconds: " + millis0);3031    // 12-hour format components32    int hour24→ 9 = time.getHour();33    int hour12→ 9 = hour249 % 12;34    if (hour12 == 0) hour12 = 12;35    String amPm→ AM = hour249 < 12 ? "AM" : "PM";36    37    System.out.println("\n12-hour format:");38    System.out.println("Hour (12): " + hour129);39    System.out.println("AM/PM: " + amPmAM);40    System.out.println("Time: " + String.format("%d:%02d %s", 41        hour129, time.getMinute(), amPmAM));4243    // Truncate precision44    LocalTime toMinute→ 09:05 = time.withSecond(0).withNano(0);45    LocalTime toSecond→ 09:05 = time.withNano(0);46    47    System.out.println("\nTruncated:");48    System.out.println("Original: " + time09:05);49    System.out.println("To minute: " + toMinute09:05);50    System.out.println("To second: " + toSecond09:05);5152    // Check if before/after noon53    System.out.println("\nIs before noon: " + time.isBefore(LocalTime.NOON));54    System.out.println("Is after noon: " + time.isAfter(LocalTime.NOON));5556    // Time periods57    System.out.println("\nTime period:");58    if (time.getHour() < 12) {
    outputTime: 09:05
Hour: 9
Minute: 5
Second: 0
Nanosecond: 0

Second of day: 32700
Nano of day: 32700000000000

Milliseconds: 0

12-hour format:
Hour (12): 9
AM/PM: AM
Time: 9:05 AM

Truncated:
Original: 09:05
To minute: 09:05
To second: 09:05

Is before noon: true
Is after noon: false

Time period:

  2. if (time.getHour() < 12)

    57System.out.println("\nTime period:");58if (time.getHour() < 12) {59    System.out.println("Morning");60} else if (time.getHour() < 17) {
    outputMorning

  3. LocalTime[] times =

    68// Display various times69System.out.println("\nVarious times of day:");70LocalTime[] times = {71    LocalTime.of(6, 0),72    LocalTime.of(12, 0),73    LocalTime.of(18, 0),74    LocalTime.of(23, 59)75};
    output
Various times of day:

  4. for (LocalTime t : times)

    pass 1 of 4
    77for (LocalTime t06:00 : times) {78    System.out.println(t06:00 + " - " + t.getHour() + "h " + 79                     t.getMinute() + "m");80}
    output06:00 - 6h 0m
    All 4 passes — pass 1 is the card above
    passt
    106:00
    212:00
    318:00
    423:59
time_components Individual parts of a time that can be extracted: hour (0-23), minute (0-59), second (0-59), nanosecond.

Comparing Times

check
Compare.java
Replay: real traced execution (multi-file project)
// Compare times

import java.time.LocalTime;

public class Compare {

    public static void main(String[] args) {
        LocalTime time1 = LocalTime.of(9, 30);
        LocalTime time2 = LocalTime.of(14, 45);
        LocalTime time3 = LocalTime.of(9, 30);

        System.out.println("Time 1: " + time1);
        System.out.println("Time 2: " + time2);
        System.out.println("Time 3: " + time3);
        System.out.println();

        // isBefore, isAfter
        System.out.println("time1.isBefore(time2): " + time1.isBefore(time2));
        System.out.println("time1.isAfter(time2): " + time1.isAfter(time2));

        // equals
        System.out.println("\ntime1.equals(time2): " + time1.equals(time2));
        System.out.println("time1.equals(time3): " + time1.equals(time3));

        // compareTo
        System.out.println("\ntime1.compareTo(time2): " + time1.compareTo(time2));
        System.out.println("time2.compareTo(time1): " + time2.compareTo(time1));
        System.out.println("time1.compareTo(time3): " + time1.compareTo(time3));

        // Current time comparisons
        LocalTime now = LocalTime.of(13, 15);
        System.out.println("\nSample now: " + now);
        System.out.println("9:30 is before now: " + time1.isBefore(now));
        System.out.println("14:45 is after now: " + time2.isAfter(now));

        // Find earliest/latest
        LocalTime earliest = time1.isBefore(time2) ? time1 : time2;
        LocalTime latest = time1.isAfter(time2) ? time1 : time2;

        System.out.println("\nEarliest: " + earliest);
        System.out.println("Latest: " + latest);

        // Check if in time range
        LocalTime check = LocalTime.of(12, 0);
        LocalTime start = LocalTime.of(9, 0);
        LocalTime end = LocalTime.of(17, 0);

        boolean inRange = !check.isBefore(start) && !check.isAfter(end);
        System.out.println("\n" + check + " in range [" + start + ", " + end + "]: " + inRange);

        // Sort times
        LocalTime[] times = {
            LocalTime.of(15, 30),
            LocalTime.of(9, 0),
            LocalTime.of(12, 15)
        };

        System.out.println("\nBefore sort:");
        for (LocalTime t : times) {
            System.out.println("  " + t);
        }

        java.util.Arrays.sort(times);

        System.out.println("After sort:");
        for (LocalTime t : times) {
            System.out.println("  " + t);
        }

        // Business hours check
        LocalTime businessStart = LocalTime.of(9, 0);
        LocalTime businessEnd = LocalTime.of(17, 0);

        System.out.println("\nBusiness hours check:");
        LocalTime[] testTimes = {
            LocalTime.of(8, 30),
            LocalTime.of(12, 0),
            LocalTime.of(18, 0)
        };

        for (LocalTime t : testTimes) {
            boolean isDuringBusiness = !t.isBefore(businessStart) && t.isBefore(businessEnd);
            System.out.println(t + " during business: " + isDuringBusiness);
        }

        // Midnight crossing
        LocalTime late = LocalTime.of(23, 0);
        LocalTime early = LocalTime.of(1, 0);
        System.out.println("\n23:00 is before 01:00: " + late.isBefore(early));
    }

}

// Compare times

import java.time.LocalTime;

public class Compare {

    public static void main(String[] args) {
        LocalTime time1 = LocalTime.of(9, 30);
        LocalTime time2 = LocalTime.of(14, 45);
        LocalTime time3 = LocalTime.of(9, 30);

        System.out.println("Time 1: " + time1);
        System.out.println("Time 2: " + time2);
        System.out.println("Time 3: " + time3);
        System.out.println();

        // isBefore, isAfter
        System.out.println("time1.isBefore(time2): " + time1.isBefore(time2));
        System.out.println("time1.isAfter(time2): " + time1.isAfter(time2));

        // equals
        System.out.println("\ntime1.equals(time2): " + time1.equals(time2));
        System.out.println("time1.equals(time3): " + time1.equals(time3));

        // compareTo
        System.out.println("\ntime1.compareTo(time2): " + time1.compareTo(time2));
        System.out.println("time2.compareTo(time1): " + time2.compareTo(time1));
        System.out.println("time1.compareTo(time3): " + time1.compareTo(time3));

        // Current time comparisons
        LocalTime now = LocalTime.of(13, 15);
        System.out.println("\nSample now: " + now);
        System.out.println("9:30 is before now: " + time1.isBefore(now));
        System.out.println("14:45 is after now: " + time2.isAfter(now));

        // Find earliest/latest
        LocalTime earliest = time1.isBefore(time2) ? time1 : time2;
        LocalTime latest = time1.isAfter(time2) ? time1 : time2;

        System.out.println("\nEarliest: " + earliest);
        System.out.println("Latest: " + latest);

        // Check if in time range
        LocalTime check = LocalTime.of(18, 30);
        LocalTime start = LocalTime.of(9, 0);
        LocalTime end = LocalTime.of(17, 0);

        boolean inRange = !check.isBefore(start) && !check.isAfter(end);
        System.out.println("\n" + check + " in range [" + start + ", " + end + "]: " + inRange);

        // Sort times
        LocalTime[] times = {
            LocalTime.of(15, 30),
            LocalTime.of(9, 0),
            LocalTime.of(12, 15)
        };

        System.out.println("\nBefore sort:");
        for (LocalTime t : times) {
            System.out.println("  " + t);
        }

        java.util.Arrays.sort(times);

        System.out.println("After sort:");
        for (LocalTime t : times) {
            System.out.println("  " + t);
        }

        // Business hours check
        LocalTime businessStart = LocalTime.of(9, 0);
        LocalTime businessEnd = LocalTime.of(17, 0);

        System.out.println("\nBusiness hours check:");
        LocalTime[] testTimes = {
            LocalTime.of(8, 30),
            LocalTime.of(12, 0),
            LocalTime.of(18, 0)
        };

        for (LocalTime t : testTimes) {
            boolean isDuringBusiness = !t.isBefore(businessStart) && t.isBefore(businessEnd);
            System.out.println(t + " during business: " + isDuringBusiness);
        }

        // Midnight crossing
        LocalTime late = LocalTime.of(23, 0);
        LocalTime early = LocalTime.of(1, 0);
        System.out.println("\n23:00 is before 01:00: " + late.isBefore(early));
    }

}

  1. time1 ← 09:30, time2 ← 14:45, time3 ← 09:30, now ← 13:15, earliest ← 09:30

    7public static void main(String[] args) {8    LocalTime time1→ 09:30 = LocalTime.of(9, 30);9    LocalTime time2→ 14:45 = LocalTime.of(14, 45);10    LocalTime time3→ 09:30 = LocalTime.of(9, 30);1112    System.out.println("Time 1: " + time109:30);13    System.out.println("Time 2: " + time214:45);14    System.out.println("Time 3: " + time309:30);15    System.out.println();1617    // isBefore, isAfter18    System.out.println("time1.isBefore(time2): " + time1.isBefore(time214:45));19    System.out.println("time1.isAfter(time2): " + time1.isAfter(time214:45));2021    // equals22    System.out.println("\ntime1.equals(time2): " + time1.equals(time214:45));23    System.out.println("time1.equals(time3): " + time1.equals(time309:30));2425    // compareTo26    System.out.println("\ntime1.compareTo(time2): " + time1.compareTo(time214:45));27    System.out.println("time2.compareTo(time1): " + time2.compareTo(time109:30));28    System.out.println("time1.compareTo(time3): " + time1.compareTo(time309:30));2930    // Current time comparisons31    LocalTime now→ 13:15 = LocalTime.of(13, 15);32    System.out.println("\nSample now: " + now13:15);33    System.out.println("9:30 is before now: " + time1.isBefore(now13:15));34    System.out.println("14:45 is after now: " + time2.isAfter(now13:15));3536    // Find earliest/latest37    LocalTime earliest→ 09:30 = time1.isBefore(time214:45) ? time109:30 : time2;38    LocalTime latest→ 14:45 = time1.isAfter(time214:45) ? time109:30 : time2;39    40    System.out.println("\nEarliest: " + earliest09:30);41    System.out.println("Latest: " + latest14:45);4243    // Check if in time range44    LocalTime check→ 12:00 = LocalTime.of(12, 0); //@check=LocalTime.of(12, 0), LocalTime.of(18, 30)45    LocalTime start→ 09:00 = LocalTime.of(9, 0);46    LocalTime end→ 17:00 = LocalTime.of(17, 0);4748    boolean inRange→ true = !check.isBefore(start09:00) && !check.isAfter(end17:00);49    System.out.println("\n" + check12:00 + " in range [" + start09:00 + ", " + end17:00 + "]: " + inRangetrue);5051    // Sort times52    LocalTime[] times = {53        LocalTime.of(15, 30),54        LocalTime.of(9, 0),55        LocalTime.of(12, 15)56    };5758    System.out.println("\nBefore sort:");59    for (LocalTime t : times) {
    outputTime 1: 09:30
Time 2: 14:45
Time 3: 09:30
time1.isBefore(time2): true
time1.isAfter(time2): false

time1.equals(time2): false
time1.equals(time3): true

time1.compareTo(time2): -1
time2.compareTo(time1): 1
time1.compareTo(time3): 0

Sample now: 13:15
9:30 is before now: true
14:45 is after now: true

Earliest: 09:30
Latest: 14:45

12:00 in range [09:00, 17:00]: true

Before sort:

  2. for (LocalTime t : times)

    pass 1 of 3
    58System.out.println("\nBefore sort:");59for (LocalTime t15:30 : times) {60    System.out.println("  " + t15:30);61}
    output  15:30
    All 3 passes — pass 1 is the card above
    passt
    115:30
    209:00
    312:15

  3. java.util.Arrays.sort(times);

    63java.util.Arrays.sort(times);6465System.out.println("After sort:");66for (LocalTime t : times) {
    outputAfter sort:

  4. for (LocalTime t : times)

    pass 1 of 3
    65System.out.println("After sort:");66for (LocalTime t09:00 : times) {67    System.out.println("  " + t09:00);68}
    output  09:00
    All 3 passes — pass 1 is the card above
    passt
    109:00
    212:15
    315:30

  5. businessStart ← 09:00, businessEnd ← 17:00

    70// Business hours check71LocalTime businessStart→ 09:00 = LocalTime.of(9, 0);72LocalTime businessEnd→ 17:00 = LocalTime.of(17, 0);7374System.out.println("\nBusiness hours check:");75LocalTime[] testTimes = {76    LocalTime.of(8, 30),77    LocalTime.of(12, 0),78    LocalTime.of(18, 0)79};
    output
Business hours check:

  6. isDuringBusiness ← false

    pass 1 of 3
    81for (LocalTime t08:30 : testTimes) {82    boolean isDuringBusiness→ false = !t.isBefore(businessStart09:00) && t.isBefore(businessEnd17:00);83    System.out.println(t08:30 + " during business: " + isDuringBusinessfalse);84}
    output08:30 during business: false
    All 3 passes — pass 1 is the card above
    passtisDuringBusiness
    108:30false
    212:00true
    318:00false

  7. late ← 23:00, early ← 01:00

    86    // Midnight crossing87    LocalTime late→ 23:00 = LocalTime.of(23, 0);88    LocalTime early→ 01:00 = LocalTime.of(1, 0);89    System.out.println("\n23:00 is before 01:00: " + late.isBefore(early01:00));90}
    output
23:00 is before 01:00: false

  1. time1 ← 09:30, time2 ← 14:45, time3 ← 09:30, now ← 13:15, earliest ← 09:30

    7public static void main(String[] args) {8    LocalTime time1→ 09:30 = LocalTime.of(9, 30);9    LocalTime time2→ 14:45 = LocalTime.of(14, 45);10    LocalTime time3→ 09:30 = LocalTime.of(9, 30);1112    System.out.println("Time 1: " + time109:30);13    System.out.println("Time 2: " + time214:45);14    System.out.println("Time 3: " + time309:30);15    System.out.println();1617    // isBefore, isAfter18    System.out.println("time1.isBefore(time2): " + time1.isBefore(time214:45));19    System.out.println("time1.isAfter(time2): " + time1.isAfter(time214:45));2021    // equals22    System.out.println("\ntime1.equals(time2): " + time1.equals(time214:45));23    System.out.println("time1.equals(time3): " + time1.equals(time309:30));2425    // compareTo26    System.out.println("\ntime1.compareTo(time2): " + time1.compareTo(time214:45));27    System.out.println("time2.compareTo(time1): " + time2.compareTo(time109:30));28    System.out.println("time1.compareTo(time3): " + time1.compareTo(time309:30));2930    // Current time comparisons31    LocalTime now→ 13:15 = LocalTime.of(13, 15);32    System.out.println("\nSample now: " + now13:15);33    System.out.println("9:30 is before now: " + time1.isBefore(now13:15));34    System.out.println("14:45 is after now: " + time2.isAfter(now13:15));3536    // Find earliest/latest37    LocalTime earliest→ 09:30 = time1.isBefore(time214:45) ? time109:30 : time2;38    LocalTime latest→ 14:45 = time1.isAfter(time214:45) ? time109:30 : time2;39    40    System.out.println("\nEarliest: " + earliest09:30);41    System.out.println("Latest: " + latest14:45);4243    // Check if in time range44    LocalTime check→ 18:30 = LocalTime.of(18, 30);45    LocalTime start→ 09:00 = LocalTime.of(9, 0);46    LocalTime end→ 17:00 = LocalTime.of(17, 0);4748    boolean inRange→ false = !check.isBefore(start09:00) && !check.isAfter(end17:00);49    System.out.println("\n" + check18:30 + " in range [" + start09:00 + ", " + end17:00 + "]: " + inRangefalse);5051    // Sort times52    LocalTime[] times = {53        LocalTime.of(15, 30),54        LocalTime.of(9, 0),55        LocalTime.of(12, 15)56    };5758    System.out.println("\nBefore sort:");59    for (LocalTime t : times) {
    outputTime 1: 09:30
Time 2: 14:45
Time 3: 09:30
time1.isBefore(time2): true
time1.isAfter(time2): false

time1.equals(time2): false
time1.equals(time3): true

time1.compareTo(time2): -1
time2.compareTo(time1): 1
time1.compareTo(time3): 0

Sample now: 13:15
9:30 is before now: true
14:45 is after now: true

Earliest: 09:30
Latest: 14:45

18:30 in range [09:00, 17:00]: false

Before sort:

  2. for (LocalTime t : times)

    pass 1 of 3
    58System.out.println("\nBefore sort:");59for (LocalTime t15:30 : times) {60    System.out.println("  " + t15:30);61}
    output  15:30
    All 3 passes — pass 1 is the card above
    passt
    115:30
    209:00
    312:15

  3. java.util.Arrays.sort(times);

    63java.util.Arrays.sort(times);6465System.out.println("After sort:");66for (LocalTime t : times) {
    outputAfter sort:

  4. for (LocalTime t : times)

    pass 1 of 3
    65System.out.println("After sort:");66for (LocalTime t09:00 : times) {67    System.out.println("  " + t09:00);68}
    output  09:00
    All 3 passes — pass 1 is the card above
    passt
    109:00
    212:15
    315:30

  5. businessStart ← 09:00, businessEnd ← 17:00

    70// Business hours check71LocalTime businessStart→ 09:00 = LocalTime.of(9, 0);72LocalTime businessEnd→ 17:00 = LocalTime.of(17, 0);7374System.out.println("\nBusiness hours check:");75LocalTime[] testTimes = {76    LocalTime.of(8, 30),77    LocalTime.of(12, 0),78    LocalTime.of(18, 0)79};
    output
Business hours check:

  6. isDuringBusiness ← false

    pass 1 of 3
    81for (LocalTime t08:30 : testTimes) {82    boolean isDuringBusiness→ false = !t.isBefore(businessStart09:00) && t.isBefore(businessEnd17:00);83    System.out.println(t08:30 + " during business: " + isDuringBusinessfalse);84}
    output08:30 during business: false
    All 3 passes — pass 1 is the card above
    passtisDuringBusiness
    108:30false
    212:00true
    318:00false

  7. late ← 23:00, early ← 01:00

    86    // Midnight crossing87    LocalTime late→ 23:00 = LocalTime.of(23, 0);88    LocalTime early→ 01:00 = LocalTime.of(1, 0);89    System.out.println("\n23:00 is before 01:00: " + late.isBefore(early01:00));90}
    output
23:00 is before 01:00: false

Combining with Date

Combine.java
Replay: real traced execution (multi-file project)
// Combine date and time

import java.time.LocalDate;
import java.time.LocalTime;
import java.time.LocalDateTime;

public class Combine {

    public static void main(String[] args) {
        LocalDate date = LocalDate.of(2025, 1, 29);
        LocalTime time = LocalTime.of(14, 30, 0);

        // Combine using atTime
        LocalDateTime dt1 = date.atTime(time);
        System.out.println("Date + Time: " + dt1);

        // Combine using atDate
        LocalDateTime dt2 = time.atDate(date);
        System.out.println("Time + Date: " + dt2);

        // Combine using LocalDateTime.of
        LocalDateTime dt3 = LocalDateTime.of(date, time);
        System.out.println("LocalDateTime.of: " + dt3);

        // Shorthand combinations
        LocalDateTime dt4 = date.atTime(14, 30);
        System.out.println("\nShorthand (HH:MM): " + dt4);

        LocalDateTime dt5 = date.atTime(14, 30, 45);
        System.out.println("Shorthand (HH:MM:SS): " + dt5);

        // Start and end of day
        LocalDateTime startOfDay = date.atStartOfDay();
        LocalDateTime endOfDay = date.atTime(LocalTime.MAX);

        System.out.println("\nStart of day: " + startOfDay);
        System.out.println("End of day: " + endOfDay);

        // Extract date and time from datetime
        LocalDateTime now = LocalDateTime.of(2025, 1, 29, 14, 30, 45);
        LocalDate extractedDate = now.toLocalDate();
        LocalTime extractedTime = now.toLocalTime();

        System.out.println("\nNow: " + now);
        System.out.println("Extracted date: " + extractedDate);
        System.out.println("Extracted time: " + extractedTime);

        // Common datetime patterns
        System.out.println("\nCommon datetimes:");

        // Today at specific time
        LocalDate today = LocalDate.of(2025, 1, 29);
        LocalDateTime todayAt9 = today.atTime(9, 0);
        System.out.println("Today at 9:00: " + todayAt9);

        // Tomorrow at noon
        LocalDateTime tomorrowNoon = today.plusDays(1).atTime(LocalTime.NOON);
        System.out.println("Tomorrow at noon: " + tomorrowNoon);

        // Next Monday at 9 AM
        int daysUntilMonday = (8 - today.getDayOfWeek().getValue()) % 7;
        if (daysUntilMonday == 0) daysUntilMonday = 7;
        LocalDateTime nextMonday9AM = today.plusDays(daysUntilMonday).atTime(9, 0);
        System.out.println("Next Monday 9 AM: " + nextMonday9AM);

        // Schedule times
        System.out.println("\nScheduled times for tomorrow:");
        LocalDate tomorrow = today.plusDays(1);
        LocalTime[] scheduleTimes = {
            LocalTime.of(9, 0),
            LocalTime.of(11, 30),
            LocalTime.of(14, 0),
            LocalTime.of(16, 30)
        };

        for (LocalTime t : scheduleTimes) {
            System.out.println("  " + tomorrow.atTime(t));
        }
    }

}

  1. date ← 2025-01-29, time ← 14:30, dt1 ← 2025-01-29T14:30, dt2 ← 2025-01-29T14:30

    9public static void main(String[] args) {10    LocalDate date→ 2025-01-29 = LocalDate.of(2025, 1, 29);11    LocalTime time→ 14:30 = LocalTime.of(14, 30, 0);1213    // Combine using atTime14    LocalDateTime dt1→ 2025-01-29T14:30 = date.atTime(time14:30);15    System.out.println("Date + Time: " + dt12025-01-29T14:30);1617    // Combine using atDate18    LocalDateTime dt2→ 2025-01-29T14:30 = time.atDate(date2025-01-29);19    System.out.println("Time + Date: " + dt22025-01-29T14:30);2021    // Combine using LocalDateTime.of22    LocalDateTime dt3→ 2025-01-29T14:30 = LocalDateTime.of(date2025-01-29, time14:30);23    System.out.println("LocalDateTime.of: " + dt32025-01-29T14:30);2425    // Shorthand combinations26    LocalDateTime dt4→ 2025-01-29T14:30 = date.atTime(14, 30);27    System.out.println("\nShorthand (HH:MM): " + dt42025-01-29T14:30);2829    LocalDateTime dt5→ 2025-01-29T14:30:45 = date.atTime(14, 30, 45);30    System.out.println("Shorthand (HH:MM:SS): " + dt52025-01-29T14:30:45);3132    // Start and end of day33    LocalDateTime startOfDay→ 2025-01-29T00:00 = date.atStartOfDay();34    LocalDateTime endOfDay→ 2025-01-29T23:59:59.999999999 = date.atTime(LocalTime.MAX);35    36    System.out.println("\nStart of day: " + startOfDay2025-01-29T00:00);37    System.out.println("End of day: " + endOfDay2025-01-29T23:59:59.999999999);3839    // Extract date and time from datetime40    LocalDateTime now→ 2025-01-29T14:30:45 = LocalDateTime.of(2025, 1, 29, 14, 30, 45);41    LocalDate extractedDate→ 2025-01-29 = now.toLocalDate();42    LocalTime extractedTime→ 14:30:45 = now.toLocalTime();43    44    System.out.println("\nNow: " + now2025-01-29T14:30:45);45    System.out.println("Extracted date: " + extractedDate2025-01-29);46    System.out.println("Extracted time: " + extractedTime14:30:45);4748    // Common datetime patterns49    System.out.println("\nCommon datetimes:");50    51    // Today at specific time52    LocalDate today→ 2025-01-29 = LocalDate.of(2025, 1, 29);53    LocalDateTime todayAt9→ 2025-01-29T09:00 = today.atTime(9, 0);54    System.out.println("Today at 9:00: " + todayAt92025-01-29T09:00);55    56    // Tomorrow at noon57    LocalDateTime tomorrowNoon→ 2025-01-30T12:00 = today.plusDays(1).atTime(LocalTime.NOON);58    System.out.println("Tomorrow at noon: " + tomorrowNoon2025-01-30T12:00);59    60    // Next Monday at 9 AM61    int daysUntilMonday→ 5 = (8 - today.getDayOfWeek().getValue()) % 7;62    if (daysUntilMonday == 0) daysUntilMonday = 7;63    LocalDateTime nextMonday9AM→ 2025-02-03T09:00 = today.plusDays(daysUntilMonday5).atTime(9, 0);64    System.out.println("Next Monday 9 AM: " + nextMonday9AM2025-02-03T09:00);6566    // Schedule times67    System.out.println("\nScheduled times for tomorrow:");68    LocalDate tomorrow→ 2025-01-30 = today.plusDays(1);69    LocalTime[] scheduleTimes = {70        LocalTime.of(9, 0),71        LocalTime.of(11, 30),72        LocalTime.of(14, 0),73        LocalTime.of(16, 30)74    };
    outputDate + Time: 2025-01-29T14:30
Time + Date: 2025-01-29T14:30
LocalDateTime.of: 2025-01-29T14:30

Shorthand (HH:MM): 2025-01-29T14:30
Shorthand (HH:MM:SS): 2025-01-29T14:30:45

Start of day: 2025-01-29T00:00
End of day: 2025-01-29T23:59:59.999999999

Now: 2025-01-29T14:30:45
Extracted date: 2025-01-29
Extracted time: 14:30:45

Common datetimes:
Today at 9:00: 2025-01-29T09:00
Tomorrow at noon: 2025-01-30T12:00
Next Monday 9 AM: 2025-02-03T09:00

Scheduled times for tomorrow:

  2. for (LocalTime t : scheduleTimes)

    pass 1 of 4
    76for (LocalTime t09:00 : scheduleTimes) {77    System.out.println("  " + tomorrow.atTime(t09:00));78}
    output  2025-01-30T09:00
    All 4 passes — pass 1 is the card above
    passt
    109:00
    211:30
    314:00
    416:30
LocalDateTime Combines LocalDate and LocalTime into a single object representing both date and time.

Key Methods

  • now(): Current time
  • of(hour, minute, second): Create specific time
  • getHour(), getMinute(), getSecond(): Get components
  • plusHours(), minusMinutes(): Add/subtract time
  • isBefore(), isAfter(): Compare times
  • parse(): From string

Common Operations

  • Add/subtract hours, minutes, seconds
  • Compare times
  • Format to string
  • Combine with date to make LocalDateTime

Immutability

LocalTime is immutable - operations return new instances.

Exercise: Practical.java

Check if a given time falls within business hours (9:00 AM to 5:00 PM)