R: Extract Parts of a POSIXt or Date Object

weekdays {base}

R Documentation

Extract Parts of a POSIXt or Date Object

Description

Extract the weekday, month or quarter, or the Julian time (days since some origin). These are generic functions: the methods for the internal date-time classes are documented here.

Usage

weekdays(x, abbreviate)
## S3 method for class 'POSIXt':
weekdays(x, abbreviate = FALSE)
## S3 method for class 'Date':
weekdays(x, abbreviate = FALSE)

months(x, abbreviate)
## S3 method for class 'POSIXt':
months(x, abbreviate = FALSE)
## S3 method for class 'Date':
months(x, abbreviate = FALSE)

quarters(x, abbreviate)
## S3 method for class 'POSIXt':
quarters(x, ...)
## S3 method for class 'Date':
quarters(x, ...)

julian(x, ...)
## S3 method for class 'POSIXt':
julian(x, origin = as.POSIXct("1970-01-01", tz="GMT"), ...)
## S3 method for class 'Date':
julian(x, origin = as.Date("1970-01-01"), ...)

Arguments

`x`	an object inheriting from class `"POSIXt"` or `"Date"`.
`abbreviate`	logical. Should the names be abbreviated?
`origin`	an length-one object inheriting from class `"POSIXt"` or `"Date"`.
`...`	arguments for other methods.

Value

weekdays and months return a character vector of names in the locale in use.
quarters returns a character vector of "Q1" to "Q4".
julian returns the number of days (possibly fractional) since the origin, with the origin as a "origin" attribute.

Note

Other components such as the day of the month or the year are very easy to compute: just use as.POSIXlt and extract the relevant component.

Examples

weekdays(.leap.seconds)
months(.leap.seconds)
quarters(.leap.seconds)

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