ADMINISTRATION: Add additional publication timing options for schedules for "Publish full day (planned)": 6 Hours and 12 Hours before the start of the day.

Affected Users:
Admins

• Task Affected:
  Publishing availabilities closer to the start of the day

• Impact:
  Some services are currently published too far in advance, leading to slots appearing as unavailable when demand actually occurs closer to the same day.

• Current State:
  Admins can only choose to publish availabilities between 24 hours and 4 weeks before the start of the day.

• Competition Consideration:
  N/A