Describe the Bug:
The headers on the schedule shifts page are using the schedule's timezone instead of the user's local timezone. "Today..." and "Tomorrow..." headers will be incorrect for users/schedules on differing timezones. (see screenshot)

Steps to Reproduce:

1. Go to Schedules (must be using a different timezone than local)
2. Click on Shifts
3. See error

Expected Behavior:
The shift headers should be using the user's local timezone.

Observed Behavior:
For users with CST local TZ and schedules on Asia/Kolkata TZ (GMT+5:30), the user's shift headers will be ahead by 11 hours and 30 minutes.

Screenshots/Stack Traces: