A free program for Android, by Sociosoftware.

Fasting Time is a simple app for calculating and tracking your fasting hours. It lets you calculate the amount of time you have to fast, and how many hours you have left before you can eat. It also allows you to set goals, so you can get motivated and focused.

The app is suitable for anyone who wants to fast for more than just health reasons. You can use the app to fast for fitness, for business, for a concert, for a movie, for a sports event, or for any other event.

The fasts can be done for one day, or for multiple days. It’s up to you.