Will my 30-day extension start from the 28th or the 2nd if I apply before my 45-day stamp expires?

A user inquired whether their 30-day visa extension would begin on their application date (December 28th) or after their current stamp expired (January 2nd). Community members confirmed that extensions are added to the expiration date, meaning the new extension would start from the 2nd of January, and advised applying early to avoid potential closure during a holiday weekend.