[Timer Start] When the timer shows 0.03, the edge of Course 51 is not yet red. This means the timer starts at least 0.03 seconds faster.

[Timer Stop] Timing ends when the pop-up after course 60 is visible at the bottom of the screen. At that time, the timer shows 1:46.90.

1:46.90 - 0.03 = 1.46.87, and rounding it, I got 1:46.9