Dates and Time Concepts

Compare Dates

Date objects can be compared to decide whether an event is early, on time, or late.

comparison Compare fixed date objects and convert the result into a clear scalar label.

Compare Dates

shipDay
compare_dates.php
Replay: real traced execution (multi-file project)
<?php
$shipDay = "2026-06-05";
$due = new DateTimeImmutable("2026-06-05", new DateTimeZone("UTC"));
$ship = new DateTimeImmutable($shipDay, new DateTimeZone("UTC"));

if ($ship < $due) {
    $status = "early";
} elseif ($ship > $due) {
    $status = "late";
} else {
    $status = "on_time";
}

echo "shipDay=" . $shipDay . "\n";
echo "status=" . $status . "\n";

<?php
$shipDay = "2026-05-30";
$due = new DateTimeImmutable("2026-06-05", new DateTimeZone("UTC"));
$ship = new DateTimeImmutable($shipDay, new DateTimeZone("UTC"));

if ($ship < $due) {
    $status = "early";
} elseif ($ship > $due) {
    $status = "late";
} else {
    $status = "on_time";
}

echo "shipDay=" . $shipDay . "\n";
echo "status=" . $status . "\n";

<?php
$shipDay = "2026-06-10";
$due = new DateTimeImmutable("2026-06-05", new DateTimeZone("UTC"));
$ship = new DateTimeImmutable($shipDay, new DateTimeZone("UTC"));

if ($ship < $due) {
    $status = "early";
} elseif ($ship > $due) {
    $status = "late";
} else {
    $status = "on_time";
}

echo "shipDay=" . $shipDay . "\n";
echo "status=" . $status . "\n";

  1. $shipDay ← 2026-06-05, $due ← DateTimeImmutable, $ship ← DateTimeImmutable

    1<?php2$shipDay→ 2026-06-05 = "2026-06-05"; //@shipDay="2026-05-30", "2026-06-10"3$due→ DateTimeImmutable = new DateTimeImmutable("2026-06-05", new DateTimeZone("UTC"));4$ship→ DateTimeImmutable = new DateTimeImmutable($shipDay2026-06-05, new DateTimeZone("UTC"));56if ($ship < $due) {7    $status = "early";8} elseif ($ship > $due) {9    $status = "late";10} else {11    $status→ on_time = "on_time";12}1314echo "shipDay=" . $shipDay2026-06-05 . "\n";15echo "status=" . $statuson_time . "\n";
    outputshipDay=2026-06-05
status=on_time

  1. $shipDay ← 2026-05-30, $due ← DateTimeImmutable, $ship ← DateTimeImmutable

    1<?php2$shipDay→ 2026-05-30 = "2026-05-30";3$due→ DateTimeImmutable = new DateTimeImmutable("2026-06-05", new DateTimeZone("UTC"));4$ship→ DateTimeImmutable = new DateTimeImmutable($shipDay2026-05-30, new DateTimeZone("UTC"));

  2. $status ← early

    6if ($shipDateTimeImmutable < $dueDateTimeImmutable) {7    $status→ early = "early";8} elseif ($ship > $due) {

  3. echo "shipDay=" . $shipDay . " ";

    14echo "shipDay=" . $shipDay2026-05-30 . "\n";15echo "status=" . $statusearly . "\n";
    outputshipDay=2026-05-30
status=early

  1. $shipDay ← 2026-06-10, $due ← DateTimeImmutable, $ship ← DateTimeImmutable

    1<?php2$shipDay→ 2026-06-10 = "2026-06-10";3$due→ DateTimeImmutable = new DateTimeImmutable("2026-06-05", new DateTimeZone("UTC"));4$ship→ DateTimeImmutable = new DateTimeImmutable($shipDay2026-06-10, new DateTimeZone("UTC"));56if ($ship < $due) {7    $status = "early";8} elseif ($ship > $due) {9    $status→ late = "late";10} else {11    $status = "on_time";12}1314echo "shipDay=" . $shipDay2026-06-10 . "\n";15echo "status=" . $statuslate . "\n";
    outputshipDay=2026-06-10
status=late