Info Node: (tar.info)Relative items in date strings
(tar.info)Relative items in date strings
Relative items in date strings
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"Relative items" adjust a date (or the current date if none) forward
or backward. The effects of relative items accumulate. Here are some
examples:
1 year
1 year ago
3 years
2 days
The unit of time displacement may be selected by the string `year'
or `month' for moving by whole years or months. These are fuzzy units,
as years and months are not all of equal duration. More precise units
are `fortnight' which is worth 14 days, `week' worth 7 days, `day'
worth 24 hours, `hour' worth 60 minutes, `minute' or `min' worth 60
seconds, and `second' or `sec' worth one second. An `s' suffix on
these units is accepted and ignored.
The unit of time may be preceded by a multiplier, given as an
optionally signed number. Unsigned numbers are taken as positively
signed. No number at all implies 1 for a multiplier. Following a
relative item by the string `ago' is equivalent to preceding the unit
by a multiplier with value -1.
The string `tomorrow' is worth one day in the future (equivalent to
`day'), the string `yesterday' is worth one day in the past (equivalent
to `day ago').
The strings `now' or `today' are relative items corresponding to
zero-valued time displacement, these strings come from the fact a
zero-valued time displacement represents the current time when not
otherwise changed by previous items. They may be used to stress other
items, like in `12:00 today'. The string `this' also has the meaning
of a zero-valued time displacement, but is preferred in date strings
like `this thursday'.
When a relative item causes the resulting date to cross a boundary
where the clocks were adjusted, typically for daylight-saving time, the
resulting date and time are adjusted accordingly.