v.timestamp

NAME

v.timestamp print/add/remove a timestamp for a vector map
(GRASS Vector Module)

SYNOPSIS

v.timestamp
v.timestamp help
v.timestamp map=name [date=timestamp[/timestamp]]

DESCRIPTION

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

OPTIONS

Parameters:

map=name: Name of vector map.
date=timestamp[/timestamp] or none: String specifying timestamp, range, or none. See FORMAT 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 vector map, use date=none.

EXAMPLES

v.timestamp map=soils
Prints the timestamp for the "soils" vector 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).

v.timestamp map=soils date='15 sep 1987'
Sets the timestamp for "soils" to the single date
"15 sep 1987"

v.timestamp map=soils date='15 sep 1987/20 feb 1988'
Sets the timestamp for "soils" to have the start date
"15 sep 1987" and the end date "20 feb 1988"

v.timestamp map=soils date=none
Removes the timestamp for the "soils" vector map

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 as of Feb, 1996 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. Some examples will help clarify:

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) mintue is 0-59 second is 0-59.9999 (fractions of second allowed) timezone is +hhmm or -hhmm (eg, -0600)

parts can be missing

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

BUGS

Spaces in the timestamp value are required.

AUTHOR

Markus Neteler, Institute of Physical Geography and Landscape Ecology, University of Hannover
based on r.timestamp by Michael Shapiro,
U.S.Army Construction Engineering Research Laboratory

Last changed: $Date: 2003/03/06 05:43:50 $