Summary

The "Log Work" functionality is using the JIRA System "Default user time zone" to set the "Date Started".
It should be using the "User Time zone" set in the Profile section

Steps to Reproduce

1. Go to an issue, click on "Log Work" and check the Time in "Date Started"
2. Change your user timezone by going to your Profile
3. Refresh the issue
4. Click on "Log Work" and check the "Date Started" field again

Expected Results

The Time defaults to the timezone recently set in the profile

Actual Results

The Time remains the same as before because it still uses the JIRA "Default user time zone"

Notes

Changing the JIRA "Default user time zone" under "General Configuration" will change the time shown by default by the "Log Work", confirming the link between them.
All other dates in the issues, such as Created, Updated, Comment times, change accordingly to the user timezone.