Generate Regular Sequences of Dates (original) (raw)

seq.Date {base}	R Documentation

Description

The method for [seq](../../base/help/seq.html) for objects of class"[Date](../../base/help/Date.html)" representing calendar dates.

Usage

## S3 method for class 'Date'
seq(from, to, by, length.out = NULL, along.with = NULL, ...)

Arguments

from	starting date; optional.
to	end date; optional.
by	increment of the sequence; optional. See ‘Details’.
length.out	integer, optional. Desired length of the sequence.
along.with	optional; take the length from the length of this argument.
...	arguments passed to or from other methods.

Details

by can be specified in several ways.

A number, taken to be in days.
A object of class [difftime](../../base/help/difftime.html)
A character string, containing one of "day","week", "month", "quarter" or "year", or a[pmatch](../../base/help/pmatch.html)()able abbreviation of these. This can optionally be preceded by a (positive or negative) integer and a space, or followed by "s".
See [seq.POSIXt](../../base/help/seq.POSIXt.html) for the details of "month".
In the case seq(from, to), the default for by is"day" (or "1 day").

Value

A vector of class "Date". Type "[integer](../../base/help/integer.html)" is often preserved on purpose, saving[object.size](../../utils/html/object.size.html).

Examples

## first days of years
seq(as.Date("1910/1/1"), as.Date("1999/1/1"), "years")
## by month
seq(as.Date("2000/1/1"), by = "month", length.out = 12)
## quarters
seq(as.Date("2000/1/1"), as.Date("2003/1/1"), by = "quarter")

## 3-week period ending on a fixed date
seq(to = as.Date("2024-06-18"), by = "day", length.out = 21)

## find all 7th of the month _strictly_ inside two dates, the last being a 7th.
st <- as.Date("1998-12-17")
en <- as.Date("2000-1-7")
ll <- seq(en, st, by = "-1 month")
rev(ll[st < ll & ll < en])

## can abbreviate 'month' to 'm':
identical(seq(st, en, by = "m"),
          seq(st, en, by = "1 month"))

[Package _base_ version 4.6.0 Index]