What does the expiration date on a multi-entry visa mean regarding its usage and activation?

@Paulie *******

ok. It’s activated the day it’s issued. You can enter Thailand as many times as you like up until the valid until date. Each entry you’ll get 60 days and you can extend that once at a local immigration office or do a border bounce and get your next 60 days. If you time it that you do a border bounce on or just before the day it expires you can get almost 9 months from that visa.