Schedules in Zendesk are like schedules in most other things: windows of time. We use these to determine business hours and various regional working hours.
Note: Brisbane was chosen as the reference timezone for APAC as daylight saving time is not observed there.
All schedules should utilize the same holidays. The ones we currently put into Zendesk are:
On those day, the schedules "stop", which results in the SLA clock not moving. This allows for Support to actually have those holidays "off".