rcs: Date option
2.1.2 Date option
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Some commands accept an option of the form ‘-dDATE’ to specify a “date”,
an absolute point in time (to second resolution), expressed in a “date
format”. These also accept ‘-zZONE’ to specify the timezone. The
special value ‘LT’ stands for the “local time zone”. RCS recognizes
many date formats and time zones. For example, the following dates are
equivalent if local time is January 11, 1990, 8pm Pacific Standard Time,
eight hours west of Coordinated Universal Time (UTC):
8:00 pm lt
4:00 AM, Jan. 12, 1990 default is UTC
1990-01-12 04:00:00+00 ISO 8601 (UTC)
1990-01-11 20:00:00-08 ISO 8601 (local time)
1990/01/12 04:00:00 traditional RCS format
Thu Jan 11 20:00:00 1990 LT output of ctime(3) + LT
Thu Jan 11 20:00:00 PST 1990 output of date(1)
Fri Jan 12 04:00:00 GMT 1990
Thu, 11 Jan 1990 20:00:00 -0800 Internet RFC 822
12-January-1990, 04:00 WET
Most fields in the date and time can be defaulted. The default time
zone is normally UTC, but this can be overridden by the ‘-z’ option.
The other defaults are determined in the order year, month, day, hour,
minute, and second (most to least significant). At least one of these
fields must be provided. For omitted fields that are of higher
significance than the highest provided field, the time zone’s current
values are assumed. For all other omitted fields, the lowest possible
values are assumed. For example, without ‘-z’, the date ‘20, 10:30’
defaults to ‘10:30:00 UTC’ of the 20th of the UTC time zone’s current
month and year. Note that for the shell, the date/time must be quoted
if it contains spaces.
RCS also accepts some other formats which specify only the date
portion (omitting the time portion). In the following table, YEAR is
the four-digit year ‘YYYY’, and all examples specify 20 April 2018.
format example description
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YEAR-DOY ‘2018-110’ DOY is the day of year ‘DDD’, 1-366.
YEAR-wWEEK-DOW ‘2018-w16-5’ WEEK is the ISO week number ‘WW’, 0-53
(actually, ISO week numbers are 1-53;
week 0 is a GNU RCS extension); and
DOW is the ISO day number ‘D’, 1-7
(Monday through Sunday). Note the
literal ‘w’ that precedes WEEK.