Yacht timers work on 5 minute countdowns. Also sometimes info at 10 minutes and 15 minutes. This has seven holes, and interestingly there is white on both sides of the three dark holes so it’s an odd kind of countdown. Could it be connected to days of the week ?
And there’s probably a good clue with the red zone between 5 and 20 minutes, and the blue zone between 35 and 50 minutes. Is there a sport where you play for 15 minutes, have a 15 minute break, then play for a further 15 minutes ?
And edit to ask... I see no sign of any pushers. Are there any other shots the show the existence of pushers ?