How can I unsync my calendar from a Galaxy S3 that I gave to my husband when I got a S6?

[AC Question]

My old S-3 number has been changed but I can't seem to unsync the google calendar. My calendar is now synced to my new S-6 and my laptop. Don't want my calendar on my old S-3.

 

[B. Diddy]

Welcome to Android Central! Ideally, you should do a factory reset of the phone before giving it to anyone else, even if it's family. If you don't want to do that, then at least go to Settings>Accounts-Google, select your account, and remove it from the phone. Make sure your husband adds his Google account instead.