Fix post dates being inconsistent

[hughrun]

Makes all dates fixed except if in the last day, in which case they are relative times.

Prior to this if a post was published on the same day of the month as today, the date was shown as relative (e.g. "10 months ago").

Description

• Related Issue #
• Closes Use consistent timestamp style #3365

What type of Pull Request is this?

• Bug Fix
• Enhancement
• Plumbing / Internals / Dependencies
• Refactor

Does this PR change settings or dependencies, or break something?

• This PR changes or adds default settings, configuration, or .env values
• This PR changes or adds dependencies
• This PR introduces other breaking changes

Details of breaking or configuration changes (if any of above checked)

Documentation

• New or amended documentation will be required if this PR is merged
• I have created a matching pull request in the Documentation repository
• I intend to create a matching pull request in the Documentation repository after this PR is merged

Tests

• My changes do not need new tests
• All tests I have added are passing
• I have written tests but need help to make them pass
• I have not written tests and need help to write them

[dato]

Thanks for investigating! The fix looks good to me.

We should perhaps consider changing "M j" to "MONTH_DAY_FORMAT"?, since the former is not localized. (Not necessarily in this PR!)

(Though at the same time, the change would worsen the English localisation, since abbreviated months sound appropriate for status timestamps. MONTH_DAY_FORMAT uses full month names in English.)

[hughrun]

Ah, I did think about that but wasn't sure how to do locale-specific dates. This is a good solution and admins can override the default. I'll update the PR shortly.

[dato]

Great, thank you!

If you’d like, you can squash this test into your PR: hughrun#5

(I have a branch with extended tests for get_published_date, but I’m having errors mocking datetime.now(), so I’ll send them in a separate PR later.)