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.


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.


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.


    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]


    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


    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


    Spaces in the timestamp value are required.



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

    Last changed: $Date$