How to use Fasting in Left

Fasting keeps your planned window, active timer, reminders, history, and weekly progress together. You can start freely, follow a recurring schedule, or let local sunrise and sunset define the window.

Open Fasting

Open the tools menu and choose Fasting. If you want it in the bottom menu, open Choose your tools and pin it. Fasting is available with Left Premium.

Choose a fasting schedule

• Automatic: choose the hours and days when Left should schedule and begin a fast.
• Overnight: use a simple evening-to-morning window.
• Sunrise to sunset: use coarse location access to follow local solar times as seasons change.
• Custom: choose your own start, end, and fasting days.
• Open: start fasts freely without a recurring window.

Run, finish, and correct a fast

Choose a planned finish and tap Start fast, or wait for an automatic window. The timeline shows when the fast began, where you are now, and when the planned window ends. You can stop early or continue after the goal is reached.

Use My fasts to add a completed past fast, correct start and end times, or remove an incorrect entry. Left keeps active and completed sessions separate so edits do not create overlapping timers.

Reminders, Live Activities, widgets, and Apple Watch

Before-fast alerts can arrive one hour, thirty minutes, and at the scheduled start. During-fast alerts can arrive with three hours left, one hour left, and when the planned window completes.

Choose whether the Live Activity appears for the whole fast, only the final three hours, or stays off. Fasting widgets show the active timer, next window, and weekly progress. On Apple Watch you can start or end a fast, change schedule, and check today's summary.

Review history and statistics

History groups sessions by day and marks manually added entries. Statistics show fasting over time, average duration by weekday, duration consistency, and the mix of shorter and longer fasts.

Use Fasting safely

Left records time and progress. It does not provide medical advice, diagnose conditions, or decide whether fasting is appropriate for you. Speak with a qualified healthcare professional before fasting if you are pregnant, under 18, have an eating disorder, take medication, or have a health condition that may be affected by food or fluid restriction.