R: Generate Regular Sequences of Dates

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"`, `"quarter"` 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"`.

### Note

Quarterly increments were specified by `by = "3 months"` prior to R 3.1.0.

### 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 = "quarter")

    ## 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])

[Package base version 3.1.2 Index]