@sn1 Date & Time are usually set automatically from Location Services/carrier services. You can simply instruct the 60 end-users to navigate to Settings > General > Date & Time to change a timezone manually. However, might be you have some lock or unchecked the 'Set Automatically' feature for Date & Time. I would look into what you have disabled through your MDM moving forward. If you have Apple ID's logged into iCloud you might be able to log into www.icloud.com and reset timezone to your account, not sure of this resetting locks in place though, worth a gamble.
