Dates and Time Series

Monthly Sequence

Regular Dates

seq.Date creates regular calendar sequences. A month step controls how far each generated date advances.

Program

Play the script to change the month step and compare the generated labels.

month_step
monthly_sequence.R
Replay: real traced execution (multi-file project)
start <- as.Date("2026-01-01")
month_step <- 1
dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)
labels <- format(dates, "%b")
summary <- paste(labels, collapse = ",")
cat(summary, "\n", sep = "")

start <- as.Date("2026-01-01")
month_step <- 2
dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)
labels <- format(dates, "%b")
summary <- paste(labels, collapse = ",")
cat(summary, "\n", sep = "")

start <- as.Date("2026-01-01")
month_step <- 3
dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)
labels <- format(dates, "%b")
summary <- paste(labels, collapse = ",")
cat(summary, "\n", sep = "")

  1. start ← 2026-01-01

    1start <- as.Date("2026-01-01")2month_step <- 1
    values this step2026-01-01start

  2. month_step ← 1

    1start <- as.Date("2026-01-01")2month_step <- 13dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)
    values this step1month_step

  3. dates ← 2026-01-01, 2026-02-01, 2026-03-01, 2026-04-01

    2month_step <- 13dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)4labels <- format(dates, "%b")
    values this step2026-01-01, 2026-02-01, 2026-03-01, 2026-04-01dates2026-01-01start1month_step

  4. labels ← Jan, Feb, Mar, Apr

    3dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)4labels <- format(dates, "%b")5summary <- paste(labels, collapse = ",")
    values this stepJan, Feb, Mar, Aprlabels4 monthly datesdates

  5. summary ← Jan,Feb,Mar,Apr

    4labels <- format(dates, "%b")5summary <- paste(labels, collapse = ",")6cat(summary, "\n", sep = "")
    values this stepJan,Feb,Mar,AprsummaryJan, Feb, Mar, Aprlabels

  6. cat(summary, " ", sep = "")

    5summary <- paste(labels, collapse = ",")6cat(summary, "\n", sep = "")
    outputJan,Feb,Mar,Apr
    values this stepJan,Feb,Mar,Aprsummary

  1. start ← 2026-01-01

    1start <- as.Date("2026-01-01")2month_step <- 2
    values this step2026-01-01start

  2. month_step ← 2

    1start <- as.Date("2026-01-01")2month_step <- 23dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)
    values this step2month_step

  3. dates ← 2026-01-01, 2026-03-01, 2026-05-01, 2026-07-01

    2month_step <- 23dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)4labels <- format(dates, "%b")
    values this step2026-01-01, 2026-03-01, 2026-05-01, 2026-07-01dates2026-01-01start2month_step

  4. labels ← Jan, Mar, May, Jul

    3dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)4labels <- format(dates, "%b")5summary <- paste(labels, collapse = ",")
    values this stepJan, Mar, May, Jullabels4 two-month datesdates

  5. summary ← Jan,Mar,May,Jul

    4labels <- format(dates, "%b")5summary <- paste(labels, collapse = ",")6cat(summary, "\n", sep = "")
    values this stepJan,Mar,May,JulsummaryJan, Mar, May, Jullabels

  6. cat(summary, " ", sep = "")

    5summary <- paste(labels, collapse = ",")6cat(summary, "\n", sep = "")
    outputJan,Mar,May,Jul
    values this stepJan,Mar,May,Julsummary

  1. start ← 2026-01-01

    1start <- as.Date("2026-01-01")2month_step <- 3
    values this step2026-01-01start

  2. month_step ← 3

    1start <- as.Date("2026-01-01")2month_step <- 33dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)
    values this step3month_step

  3. dates ← 2026-01-01, 2026-04-01, 2026-07-01, 2026-10-01

    2month_step <- 33dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)4labels <- format(dates, "%b")
    values this step2026-01-01, 2026-04-01, 2026-07-01, 2026-10-01dates2026-01-01start3month_step

  4. labels ← Jan, Apr, Jul, Oct

    3dates <- seq.Date(start, by = paste(month_step, "month"), length.out = 4)4labels <- format(dates, "%b")5summary <- paste(labels, collapse = ",")
    values this stepJan, Apr, Jul, Octlabels4 quarterly datesdates

  5. summary ← Jan,Apr,Jul,Oct

    4labels <- format(dates, "%b")5summary <- paste(labels, collapse = ",")6cat(summary, "\n", sep = "")
    values this stepJan,Apr,Jul,OctsummaryJan, Apr, Jul, Octlabels

  6. cat(summary, " ", sep = "")

    5summary <- paste(labels, collapse = ",")6cat(summary, "\n", sep = "")
    outputJan,Apr,Jul,Oct
    values this stepJan,Apr,Jul,Octsummary
seq.Date `seq.Date(start, by = ..., length.out = ...)` builds regular date sequences.
month step `paste(month_step, "month")` creates a step such as `2 month`.
format `format(dates, "%b")` converts dates into month labels.