A common question might be how do you send appointment reminders to your clients in their local time zone instead of your time zone.
When you connect a calendar to Appointment Reminder it will show you what time zone the calendar is currently set for. This comes from Google and if wrong really should be changed in Google Calendar first.
If you've already connected your calendar you can go to Calendar > Edit Calendars > Edit and check the time zone the calendar is currently set for.
By default all reminders will just be sent in the same time zone as the calendar. If you want to change this then you will need to go to Calendar > Edit Calendars > Edit and turn on the switch that says "Use Client Time zone".
When you load an appointment in Google Calendar you should now set the time zone to your clients time zone when loading the appointment. The appointment will still show on YOUR calendar the correct time zone for you.
For example my local time zone is Mountain Standard Time (I live in Riverton, WY) but most of my clients are actually based in Pacific Time.
This appointment will show as 11am on my calendar but the client will get a reminder advising the appointment is 10am Pacific time.
If you don't want to this for each appointment then another option is just indicate what time zone the appointment is for in your script. Example. Hello this is a reminder you have an appointment with $BUSINESS_NAME on $APPOINTMENT_DATE_SHORT @ $APPOINTMENT_START_TIME EST. Please reply C to confirm.