Recovery is really an individual thing. Meaning it will be different for everyone depending on your health, surgery etc. However, I was told 6-8 weeks. Mine took longer because I was bullheaded and pushed more than was wise. That said it was a good 12 weeks but again I pushed it and that slowed healing.
Hi and welcome to the Chiari forum.
As CW mentioned, it is a very individual thing...many have related conditions that factor into the healing process....I am not sure exactly how long my recovery from the surgery was, but I know I discovered new benefits each year out...next May I will be 10 years post op.
And what you do, as CW indicated can cause healing to be prolonged or for set backs to occur.
All I can suggest is that you listen to your body, and let it decide how long it will take and do not rush things, I have the tortoise as my avitar because slow and steady wins the ran...same goes for recovery.