seq.Date {base}

R Documentation

Generate Regular Sequences of Dates

Description

The method for seq for objects of class class "Date" representing calendar dates.

Usage

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

Arguments

from	starting date. Required
to	end date. Optional.
by	increment of the sequence. Optional. See ‘Details’.
length.out	integer, optional. desired length of the sequence.
along.with	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

• A character string, containing one of "day", "week", "month" or "year". This can optionally be preceded by a (positive or negative) integer and a space, or followed by "s".

  See seq.POSIXt for the details of "month".

Value

A vector of class "Date".

See Also

Date

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="3 months")

## find all 7th of the month between 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[ll > st & ll < en])

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