To manage the many different International Time Zones of our community (126 countries), New York Eastern time is used as the core time from which all other regions are then converted.

New York Eastern time zone schedule (fixed)

If you live in this time zone, the times shown on the schedule are fixed.  Anyone can use this schedule to convert times to their location.  

Regional Schedules (vary)

The times shown on these schedules are a direct conversion from the New York Eastern schedule.  They will change as day light saving begins or ends in your region.  Most of these changes will happen either in March / April and October / November 

The best way to know if your schedule is going to change is to know the day light saving changes for your region - and then recheck the schedule at that time.  It is likely your class will have shifted by 1 or 2 hours. 

For example: If you are in Australia and your country is about to move away from day light saving, then the time of your class will change.  This change has been converted for you and is as shown on your schedule.    

Wikipedia have a great list of who moves and when  - Daylight saving time by country.