There are 2 places within Jasmine Practice Management for changing the timezone. The places to change are Company Information, User Information and Business Hours (for the Online Scheduling Widget).
Company Information
Click the gear icon
Click Setup
Search "Company Information"
Click Company Information
Click Edit
Set Default Time Zone
Click Save
User Information
Click the gear icon
Click Setup
Search for "Users"
Click Users menu item
Click Edit
Set Time Zone
Click Save