13-Hour Fast Starting at 1:00 PM: End Time Calculator

Last reviewed · Jun 29, 2026 · Not medical advice
Your fast ends at
2:00 AM next day
1:00 PM + 13 hours = 2:00 AM (next day)

This calculator-style page answers the timing question first, then shows how to track the same window in Fast Goblin.

Calculation

1:00 PM + 13 hours = 2:00 AM (next day)

Example fasting day

For a simple example, start your timer at 1:00 PM, keep the fast going through the full 13 hours, and break it at 2:00 AM. If that window feels awkward, move the start time instead of changing the whole plan.

Common mistakes

01 Counting from the wrong meal instead of the actual fast start.
02 Forgetting whether the end time is same day or next day.
03 Changing the plan every day before you know what timing works.
04 Using longer fasts as a shortcut instead of building a repeatable routine.

Track it in Fast Goblin

Fast Goblin can save the calculation by letting you start the fast and see the end time automatically. No more checking the clock twice and still being unsure.

How Fast Goblin helps

Fast Goblin can save the calculation by letting you start the fast and see the end time automatically. No more checking the clock twice and still being unsure.

Get the app

Common questions

What time does a 13-hour fast end if it starts at 1:00 PM?

It ends at 2:00 AM the next day.

Does the date matter?

For overnight or multi-day fasts, yes. The page shows whether the end time falls on the same day or a later day.

Can I use a different start time?

Yes. Use the calculator index or set a custom timer in Fast Goblin.

Safety note
Fast Goblin is a tracking app, not medical advice. Intermittent fasting is not for everyone; people who are under 18, pregnant or breastfeeding, have a history of eating disorders, or use insulin/diabetes medication should talk to a qualified professional before changing fasting routines.

Keep reading

Free on the App Store

Never calculate an end time again

Fast Goblin does the time math for every fast — start in one tap, see the end time instantly.