Can I change my ad account time zone?
Unfortunately ad account time zones cannot be changed.
Your ad account's time zone is imported from Facebook, and was set the moment the ad account was created.
You can change the time zone of your ad account on Facebook, but this deactivates the existing account, stops any of its running ads, and creates a new ad account with the new time zone. This new ad account will then need to be imported into Hootsuite Ads.