Log into your Start Booking account at https://app.startbooking.com.
In the top right of the Start Booking application, hover over My Account and select Settings.
On the Settings screen, toggle the Time Display to 24 Hour and click the Save button.
The Time Display setting does not cover all aspects of the Start Booking experience. This setting only updates the booking flow that your customers will see as well as the emails they receive. This does not update the entire application at this time.