When setting up an interval start time race, start times are assigned in the same order as the racer numbers. First racer number gets the first start time, second racer number gets the second start time…
If you want something else, navigate to the “Start List” tab for your race and scroll down to the Start Times section (or journey start times or stage start times second for an enduro race. The “Sort order” column displays what order the times will be assigned in – you’ll see it set to “Racer # (ascending)” in the default configuration:
To change this to something else, click the blue label, and select a different field to sort by or click the “A-Z” button to toggle between ascending or descending order.