Will My Non-B Visa Extension Be Valid From My Entry Date or Extension Date?

Guess this will be an easy one for the experts, might not even need Tod Daniels wisdom but I’d appreciate it obviously 😉

1. I entered Thailand on a non b 90 daysback in November, stamped in till February 18th

2. applied for a - year extension today, officer added 30 days on top so till March 19th

When I pick up the Passport in March, will it be stamped till 365 days from March 19th or from my initial entry date in November.

Thanks in advance!