Add $post_type argument to get_lastpostdate/get_lastpostmodified/_get_last_post_time

[duck_]

As title says. You can currently use these functions to only get the latest [modification] date of all publicly queryable content types.

[duck_]

Updated key for adding to cache, but haven't put in code for deleting it when it changes yet.

[duck_]

Haven't tested the cache invalidation in an environment with a persistent cache. Also moved the call to date('Z') to where it's needed, don't need to hit the system clock if unnecessary.

Related #14922 which added a filter for a short period.

[DrewAPicture]

There has been no interest or meaningful activity in four years. Closing as wontfix.

[SergeyBiryukov]

This would make things easier for XML sitemaps in Yoast SEO.

[SergeyBiryukov]

While we're at it, the $timezone description should be synchronized between get_lastpostdate() and _get_last_post_time(), and extra or 'server'. should be removed from get_lastpostmodified().

It would probably make sense to move the extended description from get_lastpostmodified() to get_lastpostdate() (since it comes first), and then reference it in get_lastpostmodified() and _get_last_post_time().

Leaving a note here to create a separate ticket or handle this in a separate commit.

[wonderboymusic]

In 34201:

Allow get_lastpostdate(), get_lastpostmodified(), and _get_last_post_time() to accept $post_type and cache separately.

Props _duck, SergeyBiryukov.
See #17455.

[wonderboymusic]

In 34202:

Don't redirect to the Term list table after submitting the form on the Edit Term page.

Props chiragswadia, UmeshSingla, rhyswynne, afercia.
Fixes #17455.

[SergeyBiryukov]

In 34240:

Docs: Synchronize the $timezone parameter description between get_lastpostdate(), get_lastpostmodified(), and _get_last_post_time().

See #17455.