How to use the online timer
Hours belong to the long, patient jobs. A turkey that needs three of them, a shoulder of lamb going slowly in a low oven, dough proving overnight in a cool spot, a shift at work, a long drive broken into legs between services. At this scale the exact minute rarely matters, and setting the timer in minutes just makes it harder to enter.
The point of an hour-based countdown is not precision but convenience. It runs in the background across a whole afternoon without needing to be looked at, which is exactly right for something that should not be checked every twenty minutes anyway. Opening the oven or lifting a slow cooker lid out of curiosity costs heat that takes a long time to recover, so the most useful thing about a long countdown is as permission to leave the thing alone until it finishes.