as.date               package:survival               R Documentation

Coerce Data to Dates

Description:

     Converts any of the following character forms to a Julian date:
     8/31/56, 8-31-1956, 31 8 56, 083156, 31Aug56, or August 31 1956.

Usage:

     as.date(x, order = "mdy", ...)

Arguments:

       x: input data vector.

   order: if x is character, defines the order in which the terms are
          assumed to appear in a xx/xx/xx date.  The default is
          month/day/year; any permutation of mdy is legal.

     ...: if x is character, then any other arguments from 'mdy.date()'
          can be used as well.

Details:

     If 'x' is numeric, then 'floor(x)' is returned, e.g.,
     'as.date(35)' is the same as 'as.date(35.2)' and gives 'Feb 2,
     1960'.  If 'x' is character, the program attempts to parse it.

Value:

     For each date, the number of days between it and January 1, 1960.
     The date will be missing if the string is not interpretable.

See Also:

     'mdy.date', 'date.mmddyy',  'date.ddmmmyy'

Examples:

     as.date(c("1jan1960", "2jan1960", "31mar1960", "30jul1960"))

