julian
Extract Parts of a Date or POSIXt Object

### Description

Extracts the julian time, month, quarter, or weekday from a Date or POSIXt object.

### Usage

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

### Arguments

x | a Date or POSIXt object.
origin | a Date or POSIXt object specifying the origin of the julian time.
abbreviate | a logical value specifying if the return value should be abbreviated.
... | additional arguments.

Value

julian | returns the number of days since the time origin, as a numeric vector for julian.Date and as a difftime object for julian.POSIXt, with an attribute origin.
months, quarters, weekdays | returns a character vector denoting the months, quarters, or weekdays of the time objects specified.

See Also
Date, POSIXt
Examples

    (dt <- as.Date(c("1970-01-01", "2038-01-19")))
    format(dt, "%a %b %d %H:%M:%S %Y")
    julian(dt)
    months(dt, abbreviate = TRUE)
    quarters(dt)
    weekdays(dt, abbreviate = TRUE)
    pct <- as.POSIXct(c("1970-01-01 00:00:00", "2038-01-19 03:14:07"),
       tz = "GMT")
    julian(pct)
    plt <- as.POSIXlt(c("1970-01-01 00:00:00", "2038-01-19 03:14:07"),
       tz = "")
    julian(plt, origin = as.POSIXlt("1970-01-01", tz = ""))

Package base version 6.1.5-18
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