This can be achieved from your Training Settings, and can be configured on a per day (of the week) basis:
1. Click the ‘Update training settings’ button.
2. Scroll down to the day of the week that you wish to specify a particular training time for.
3. Locate the Start time field and enter your desired value. (It may be necessary to click on ‘Schedule Workouts – Custom’ to reveal this field.)
4. Scroll to the bottom of the screen and click ‘Save’. Your plan will then be rebuilt accordingly.