How did corrie keep track of time in the hiding place?

In "The Hiding Place," Corrie ten Boom and her family kept track of time primarily through a small clock that they could hear ticking in their concealed hiding place. They also relied on their routines, such as meal times and the arrival of news from the outside world, to help them gauge the passage of time. The lack of sunlight and the oppressive atmosphere of hiding made it challenging, but they adapted as best as they could under the circumstances.