Issue Summary
Starting from Jira 9.0, Work log activity entries are showing "Date Started" timestamps in a relative way ("just now", "yesterday" etc.) instead of showing absolute date value. This behaviour differs from the previous user experience (Jira 8.22.x/8.20.x) and makes it hard to clarify the exact "Date Started" time specified during the creation of the work log entry while reviewing the details of these items.
Additional context
Unlike other activity entries where shown timestamp is the same as the entry's created date, the work log behaves differently — it shows a value specified as "Date Started" while logging the entry. For all other activity entries (like for example comments) you could hover the mouse cursor over the timestamp and check for the absolute timestamp value in the tooltip. For work log entries it will also show the correct absolute timestamp value of created date, but the tooltip doesn't show the value for the "Date Started" timestamp.

I'm logging this issue as a defect because this change is not listed in Jira 9.0 Release Notes (so it doesn't seem to be intentional). Also with this change, there is no simple way to easily check the absolute date value for"Date Started" of Work log entries.
This is reproducible on Data Center: (yes)
Steps to Reproduce
- Ensure that Administration (âš™) > Issues > Time tracking is activated
- Open any sample issue and add a work log entry (More > Log work)
- Specify "Date Started" as one day before your current date
- Review work log entry at activity Work Log tab — it will show date relatively as "Yesterday"
- Hover your mouse cursor over work log entry date — it will show "Created: <absolute timestamp>", but a created date is not always the same as "Date Started" in case of work log entries
Expected Results
The Work log activity entries should show a "full" (absolute) timestamp (like it was before 9.0) or provide an easy option to figure it out (an additional entry in the tooltip would be helpful here)
Actual Results
The Work log activity entries are showing "Date Started" timestamps are shown relatively and there is no easy way to figure out their actual value
Workaround
The "jira.lf.date.relativize = false" parameter disables relative dates (see "Display standard dates in Jira server" for additional details). However, it is worth mentioning that this property will disable relative dates globally (not only for work log), so might be not appropriate for all use cases.