[Timer Start] When the timer shows 0.04, the edge of Course 1 is not yet red. This means the timer starts at least 0.04 seconds faster.

[Timer Stop] Timing ends when the pop-up after course 10 is visible at the bottom of the screen. At that time, the timer shows 1:37.35.

1:37.35 - 0.04 = 1.37.31, and rounding it, I got 1:37.3