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convdate

NAME

convdate - Convert time/date strings and numbers

SYNOPSIS

convdate [-dhl] [-c | -n | -s] [date ...]

DESCRIPTION

convdate translates the date/time strings given on the command line, outputting the results one to a line. The input can either be a date in some format that parsedate(3) can parse or the number of seconds since epoch (if -c is given). The output is either ctime(3) results, the number of seconds since epoch, or a Usenet Date: header, depending on the options given.

OPTIONS

-c

Each argument is taken to be the number of seconds since epoch (a time_t) rather than a date.

-d

Output a valid Usenet Date: header instead of the results of ctime(3) for each date given on the command line. This is useful for testing the algorithm used to generate Date: headers for local posts. Normally, the date will be in UTC, but see the -l option.

-h

Print usage information and exit.

-l

Only makes sense in combination with -d. If given, Date: headers generated will use the local time zone instead of UTC.

-n

Rather than outputting the results of ctime(3) or a Date: header, output each date given as the number of seconds since epoch (a time_t). This option doesn't make sense in combination with -d.

-s

Pass each given date to parsedate(3) and print the results of ctime(3) (or a Date: header if -d is given). This is the default behavior.

EXAMPLES

Note that relative times or times with partial information use the current time to fill in the rest of the date, so dates like ``12pm'' are taken to be 12pm of the day when convdate is run. This is a property of parsedate(3); see the man page for more information. Most of these examples are from the original man page dating from 1991 and were run in the -0400 time zone.

    % convdate 'feb 10 10am'
    Sun Feb 10 10:00:00 1991

    % convdate 12pm 5/4/90
    Fri Dec 13 00:00:00 1991
    Fri May  4 00:00:00 1990

Note that 12pm and 5/4/90 are two *separate* arguments and therefore result in two results. Note also that a date with no time is taken to be at midnight.

    % convdate -n 'feb 10 10am' '12pm 5/4/90'
    666198000
    641880000

    % convdate -c 666198000
    Sun Feb 10 10:00:00 1991

ctime(3) results are in the local time zone. Compare to:

    % convdate -dc 666198000
    Sun, 10 Feb 1991 15:00:00 +0000 (UTC)

    % env TZ=PST8PDT convdate -dlc 666198000
    Sun, 10 Feb 1991 07:00:00 -0800 (PST)

    % env TZ=EST5EDT convdate -dlc 666198000
    Sun, 10 Feb 1991 10:00:00 -0500 (EST)

The system library functions generally use the environment variable TZ to determine (or at least override) the local time zone.

HISTORY

Written by Rich $alz <rsalz@uunet.uu.net>, rewritten and updated by Russ Allbery <rra@stanford.edu> for the -d and -l flags.

$Id: convdate.1 5132 2002-02-22 20:39:19Z vinocur $

SEE ALSO

parsedate(3).