How do I change the time zone of my contacts?

I notice the contacts I imported from my Mailchimp are put in the wrong timezone, how chan I change this?

If you want to do a mass update, go into the Contacts page, and produce a list of the imported contacts.

Click on the “Action” dropdown, and select the “Mass Update Contacts” option. Go down to the “Timezone” field and select the Time Zone they should be set to. Click on the “Process Action” at the bottom to do the update.

If the Contacts are in different Time Zones, then you will have to filter / select the ones that need to be done differently.