The update would currently include the following patches (plus some bumps of the mediawiki-codesniffer version).
- R1985:316455b75b68: Fix docs for setFakeTime()
- R1985:2be199558437: Honor timezones in input, and correct some odd accepted values
- R1985:d38a9b137b54: Improve ISO 8601 support in setTimestamp()
- R1985:43757eebb23f: Accept ISO 8601 expanded format with space in place of T
Since #2 in that list is changing how some current valid input is evaluated (e.g. "Wed, 22 May 2019 12:00:00 A potato" is now rejected, and "2019-05-22 12:00:00-04" is now correctly interpreted as 16:00 UTC rather than 12:00 UTC), this may warrant v3.0.0 rather than v2.3.0.