The Time Zone is picked from the logged-in user's browser time in the Time Review screen.
Just to clarify regarding the time displayed in the approver ID. It makes sense to show the time according to the logged-in user (approver) browser's timezone.
Especially if reporting users are spread across different timezones. This approach helps ensure clarity and consistency for the approvers, as it allows them to review time entries in a single timezone, rather than dealing with potentially confusing variations due to different timezone.
To view the time in the submitter's timezone, simply enable the "Show in Submitter Timezone" checkbox.