## DESCRIPTION

This command has 2 modes of operation. If no date argument is supplied, then the current timestamp for the raster map is printed. If a date argument is specified, then the timestamp for the raster map is set to the specified date(s). See examples below.

## NOTES

Strings containing spaces should be quoted. For specifying a range of time, the two timestamps should be separated by a forward slash. To remove the timestamp from a raster map, use date=none.

## TIMESTAMP FORMAT

The timestamp values must use the format as described in the GRASS Datetime Library. The source tree for this library should have a description of the format. For convience, the formats are reproduced here:

There are two types of datetime values:

- absolute and
- relative. Absolute values specify exact dates and/or times. Relative values specify a span of time.

  ### Absolute

  The general format for absolute values is:

        day month year [bc] hour:minute:seconds timezone

      	     day is 1-31
      	     month is jan,feb,...,dec
      	     year is 4 digit year
      	     [bc] if present, indicates dates is BC
      	     hour is 0-23 (24 hour clock)
      	     minute is 0-59
      	     second is 0-59.9999 (fractions of second allowed)
      	     timezone is +hhmm or -hhmm (eg, -0600)

  Some parts can be missing, for example

      	     1994 [bc]
      	     Jan 1994 [bc]
      	     15 jan 1000 [bc]
      	     15 jan 1994 [bc] 10 [+0000]
      	     15 jan 1994 [bc] 10:00 [+0100]
      	     15 jan 1994 [bc] 10:00:23.34 [-0500]

  ### Relative

  There are two types of relative datetime values, year-month and day-second. The formats are:

      	     [-] # years # months
      	     [-] # days # hours # minutes # seconds

  The words years, months, days, hours, minutes, seconds are literal words, and the # are the numeric values. Examples:

      	     2 years
      	     5 months
      	     2 years 5 months
      	     100 days
      	     15 hours 25 minutes 35.34 seconds
      	     100 days 25 minutes
      	     1000 hours 35.34 seconds

  The following are illegal because it mixes year-month and day-second (because the number of days in a month or in a year vary):

      	     3 months 15 days
      	     3 years 10 days

  ## EXAMPLES

  Prints the timestamp for the "soils" raster map. If there is no timestamp for "soils", nothing is printed. If there is a timestamp, one or two time strings are printed, depending on if the timestamp for the map consists of a single date or two dates (ie start and end dates).

          r.timestamp map=soils

  Sets the timestamp for "soils" to the single date "15 sep 1987".

          r.timestamp map=soils date='15 sep 1987'

  Sets the timestamp for "soils" to have the start date "15 sep 1987" and the end date "20 feb 1988".

          r.timestamp map=soils date='15 sep 1987/20 feb 1988'

  Removes the timestamp for the "soils" raster map.

          r.timestamp map=soils date=none

  ## BUGS

  Spaces in the timestamp value are required.

  ## SEE ALSO

  r.info

  ## AUTHOR

  Michael Shapiro, U.S.Army Construction Engineering Research Laboratory

  Last changed: $Date: 2012-01-28 12:54:52 -0800 (Sat, 28 Jan 2012) $