view mercurial/helptext/dates.txt @ 47072:4c041c71ec01

revlog: introduce an explicit tracking of what the revlog is about

Since the dawn of time, people have been forced to rely to lossy introspection
of the index filename to determine what the purpose and role of the revlog they
encounter is. This is hacky, error prone, inflexible, abstraction-leaky,
<insert-your-own-complaints-here>.

In f63299ee7e4d Raphaël introduced a new attribute to track this information:
`revlog_kind`. However it is initialized in an odd place and various instances
end up not having it set. In addition is only tracking some of the information
we end up having to introspect in various pieces of code.

So we add a new attribute that holds more data and is more strictly enforced.
This work is done in collaboration with Raphaël.

The `revlog_kind` one will be removed/adapted in the next changeset. We expect
to be able to clean up various existing piece of code and to simplify coming
work around the newer revlog format.

Differential Revision: https://phab.mercurial-scm.org/D10352

Some commands allow the user to specify a date, e.g.:

- backout, commit, import, tag: Specify the commit date.
- log, revert, update: Select revision(s) by date.

Many date formats are valid. Here are some examples:

- ``Wed Dec 6 13:18:29 2006`` (local timezone assumed)
- ``Dec 6 13:18 -0600`` (year assumed, time offset provided)
- ``Dec 6 13:18 UTC`` (UTC and GMT are aliases for +0000)
- ``Dec 6`` (midnight)
- ``13:18`` (today assumed)
- ``3:39`` (3:39AM assumed)
- ``3:39pm`` (15:39)
- ``2006-12-06 13:18:29`` (ISO 8601 format)
- ``2006-12-6 13:18``
- ``2006-12-6``
- ``12-6``
- ``12/6``
- ``12/6/6`` (Dec 6 2006)
- ``today`` (midnight)
- ``yesterday`` (midnight)
- ``now`` - right now

Lastly, there is Mercurial's internal format:

- ``1165411109 0`` (Wed Dec 6 13:18:29 2006 UTC)

This is the internal representation format for dates. The first number
is the number of seconds since the epoch (1970-01-01 00:00 UTC). The
second is the offset of the local timezone, in seconds west of UTC
(negative if the timezone is east of UTC).

The log command also accepts date ranges:

- ``<DATE`` - at or before a given date/time
- ``>DATE`` - on or after a given date/time
- ``DATE to DATE`` - a date range, inclusive
- ``-DAYS`` - within a given number of days from today