Recently worked on dashboard showing incorrect timestamps when clients do not have round amount Time Zones

Summary

Users that's accessing Confluence with computers that has non-round timezones (like UTC +9:30) are not seeing correct timestamps in their "Recently Worked On" page in the dashboard

Steps to reproduce

1. Set the Confluence server timezone to UTC-5
2. Set a client/user computer time zone to any non-round amount of hours and positively shifted from UTC; for example UTC+9:30 Darwin
3. Access Confluence and Edit a document.
4. Document shows "Created by USER, last modified just a moment ago".
5. Open Dashboard, "Recently worked on" shows modified "Yesterday".
6. Set computer time zone to any with round amount of hours and shifted from UTC in any direction; for example UTC+10 Brisbane.
7. Refresh "Recently worked on" — now it will properly display edited page under "Today".

Screencast attached to this bug report: Recording #15.avi

Expected Results

• Edited page should be displayed under in "Recently worked on" section under "Today" regardless of the time zone settings.

Notes

• Index rebuild from scratch doesn't help
• Time zone in user's profile is irrelevant.
• This issue does not exist for negative shifted zones, (for example, UTC -9:30 and UTC -3:30)

This issue can also be replicated with timezones that are very close to each other such as:

This doesn't seem to be due to how big is the gap between 2 timezones, but the mismatch of the minute difference

This issue is important for Confluence with users from different timezones.
This can cause confusion among users.