mercurial/helptext/dates.txt

rust: bump to memmap2 0.5.3, micro-timer 0.4.0, and crossbeam-channel 0.5.0

The merge in 12adf8c695ed had conflicts in rust/Cargo.lock and
rust/hg-core/Cargo.toml . Let's ignore rust/Cargo.lock - it is regenerated.

For rust/hg-core/Cargo.toml, stable had dd6b67d5c256 "rust: fix unsound
`OwningDirstateMap`" which introduced ouroboros (and dropped
stable_deref_trait).

Default had ec8d9b5a5e7c "rust-hg-core: upgrade dependencies" which had a lot
of churn bumping minimum versions - also patch versions. It is indeed a good
idea to bump to *allow* use of latest package. That means that major versions
should be bumped for packages after 1.0, and for packages below 1.0 minor
versions should be bumped too. But it doesn't work to try enforce a policy of
using latest patch by bumping versions at arbitrary times.

For good or bad, the merge doesn't seem to have resolved the conflicts
correctly, and many of the minor "upgrade dependencies" were lost again.

Unfortunately, it also lost the bump of memmap2 to 0.5.3, which is needed for
Fedora packaging where 0.4 isn't available. Same with micro-timer bump to 0.4
(which already is used in rhg). crossbeam-channel bump was also lost.

This change fixes that regression by redoing these "important" lines of the
merge "correctly".

I propose this for stable, even though dependency changes on stable branches
are annoying.

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