The red disk stopped moving.

If the red disk on your Original Time Timer (including Pocket, Medium and Large) stops moving, please try the following:

1. First, make sure you timer has a fresh battery if you have not replaced it recently. 
2. Next rotate the red disk clockwise from 0 to 60, and then back to 0, preferably while using a small air pump or air spray like for cleaning keyboards.  This will clear any dust or debris that might have become trapped under the disk.
3. Ensure the white face is under the 3 placement holders (located in top left section of the inside face) to prevent buckles from stopping the disk.

The video left illustrates Point 2 and 3 in action.