difftime                package:base                R Documentation

Time Intervals

Description:

     Create, print and round time intervals.

Usage:

     time1 - time2
     difftime(time1, time2, tz = "",
              units = c("auto", "secs", "mins", "hours", "days", "weeks"))
     round(x, digits = 0)

Arguments:

time1, time2: date-time objects.

      tz: A timezone specification to be used for the conversion.
          System-specific, but `""' is the current time zone, and
          `"GMT"' is UTC.

   units: character.  Units in which the results are desired. Can be
          abbreviated.

       x: An object inheriting from class `"difftime"'.

  digits: integer. Number of significant digits to retain.

Details:

     Function `difftime' takes a difference of two date/time objects
     (of either class) and returns an object of class `"difftime"' with
     an attribute indicating the units.  There is a `round' method for
     objects of this class.

     If `units = "auto"', a suitable set of units is chosen, the
     largest possible (excluding `"weeks"') in which all the absolute
     differences are greater than one.

     Subtraction of two date-time objects gives an object of this
     class, by calling `difftime' with `units="auto"'.

See Also:

     `DateTimeClasses'.

Examples:

     (z <- Sys.time() - 3600)
     Sys.time() - z                # just over 3600 seconds.

     ## time interval between releases of 1.2.2 and 1.2.3.
     ISOdate(2001, 4, 26) - ISOdate(2001, 2, 26)

