This aims to clarify the time units for some time offset values. Follow-up to [21996], [23823], [40108], [41626]. See #56791. Built from https://develop.svn.wordpress.org/trunk@54870 git-svn-id: http://core.svn.wordpress.org/trunk@54422 1a063a9b-81f0-0310-95a4-ce76da25c4cd