Free tool · Scarlet Beast En español →

When to leave: count back from the time you have to be there

An appointment at 10:15. A hearing at 9:00. A shift, a school pickup, a bus to catch. Type the time you have to be there and the minutes for each step before it: getting ready, the walk, the ride, being early. This page adds the minutes and counts back on the clock, so you can see when to start and when each step begins. It also counts forward, from the time you start to the time you get there. It shows the sum that made the answer, so you can check it on paper. There is no account and no price.

Private by design. Nothing you type is sent anywhere. Nothing is kept either, until you press Keep this plan; from then on the plans you keep stay in this browser on this device, and one button erases them. If other people use this phone or computer, they can open this page and read it. This page runs no analytics or tracking, and it does not ask where you are. How we handle privacy.

This tool needs JavaScript. The same count on paper: write down the minutes for each step and add them. Take that many minutes off the time you have to be there. An hour is 60 minutes, so 10:15 minus 30 minutes is 9:45.

Good to know

How the page counts

Everything is counted in whole minutes.
The minutes of the steps are added. 60 minutes make an hour.
Counting back: the sum is taken off the time to be there. That is the time to start. Each step begins when the one before it ends.
Counting forward: the sum is added to the time you start. That is the time you get there.
Across midnight the page says "the day before" or "the next day".
A step with no minutes is left out. A step with no name is called Step 1, Step 2 and so on.
The page only adds and counts on the clock. The minutes are the ones you type.

Examples, worked by hand.

Be there at 10:15 AM. Get ready 30 minutes, walk to the bus 10, bus ride 35, be early 15: 30 + 10 + 35 + 15 = 90 minutes, which is 1 hour 30 minutes. 10:15 AM minus 1 hour 30 minutes is 8:45 AM. Get ready at 8:45 AM, walk at 9:15 AM, bus at 9:25 AM, off the bus at 10:00 AM.
Be there at 12:30 AM for a night shift. Get ready 20 minutes, drive 25: 45 minutes. The start is 11:45 PM, the day before.
Start at 7:40 AM. Walk 12 minutes, train 48, walk 9: 12 + 48 + 9 = 69 minutes, which is 1 hour 9 minutes. There at 8:49 AM.
Be there at 1:05 PM, with one step of 80 minutes: the start is 11:45 AM.
Start at 11:20 PM, with one step of 55 minutes: there at 12:15 AM, the next day.

The examples are made up. A program checks them, and 400 made-up plans done a second way, every time the page is built.

Where clock sums trip people up

An hour is 60 minutes, not 100. 10:15 minus 30 minutes is 9:45, not 9:85. And 1 hour 30 minutes is 90 minutes, not 130.
12:00 PM is noon and 12:00 AM is midnight. 12:30 AM is half an hour after midnight, at the very start of the day. 12:30 PM is half an hour after noon.
Being early is a step. The page adds no extra minutes by itself. In the first example, without the 15 minutes the start is 9:00 AM and the bus gets in at 10:15 AM, the time itself.
Small steps add up. Five steps of 5 minutes are 25 minutes.
Waiting is a step too. The wait for a bus, a line at a door, a walk from where the car is parked: if it takes minutes, it can have its own line.

What this page does not know

It does not know traffic, weather or a late bus. It has no map, and it does not ask where you are.
It does not know when a bus or a train runs. If the bus leaves at set times, the time it leaves is the one to count back from.
It does not know how long a step takes you. Only you know that, and it can differ from day to day.
It does not know the day, so it does not know about the two nights a year when clocks change, or about another time zone.
It never says how early anyone has to be. A letter, an office, a court or a job may say; the page does not.
It counts inside one day: steps that add up to more than 24 hours are not counted.
It holds up to 20 plans on this device, and they do not move to another phone or computer by themselves.

If getting there is the hard part

On this site: When you have no ride to the doctor lists the kinds of rides there are to a medical visit, and who to call.
On this site: One step at a time breaks getting ready into small steps, for the days when starting is the hard part.

Tools that go with this

Dates to keep: every deadline and appointment on one list.
Count the days: the date a number of days away, and the days between two dates.
Get ready for your appointment: what to ask and what to bring.
My day: a picture schedule for the day.
Energy budget: plan a day around the energy you have.
Call script: what to say if you have to call and say you are running behind.
All the free tools, and how to save them on your phone.

A count, not a promise. This tool adds the minutes you give it and counts on the clock. It cannot say that you will get there by the time, and it is not legal advice about a court date or a deadline. If anyone is in danger, call 911. If things are so heavy that you are thinking about ending your life, call or text 988 (in the U.S.), or open Get help now.

The tool and the wording around it were written with AI (Claude) for Scarlet Beast (our AI policy); the times and the minutes are yours. There is no AI inside this tool: it only adds minutes and counts on the clock. It has been checked by a program, not yet used by people getting to a real appointment. What it keeps is listed on My data on this device. Also in Spanish: A qué hora salir; both pages keep the same list on this device. Found a mistake? Email [email protected].