How to use the time block planner
- Enter when the window starts and ends on the same day.
- Choose Split by length of each slot or by number of slots. For length, type the minutes per slot. For number of slots, type how many.
- Set the minutes between slots for breaks or changeovers. Use 0 for back to back.
- Read the schedule table with a start and end time for every slot. In length mode the page also shows how much time is left over after the last slot.
Formula
by length: slots fit while start + length <= end, then next start = end of slot + gap
by count: length = (window - gap x (count - 1)) / count
window = end time - start time
Times are worked out to the second. When equal slots do not come out in whole minutes, the schedule shows seconds so the last slot ends exactly at the end of the window.
A morning of 25 minute sessions
The window is 9:00 AM to 12:00 PM, which is 180 minutes. With 25 minute slots and 5 minutes between them, a slot starts every 30 minutes: 9:00, 9:30, 10:00, 10:30, 11:00 and 11:30. Six slots fit, and the last one ends at 11:55, leaving 5 minutes.
Switch to six equal slots with the same 5 minute gaps. The gaps take 5 x 5 = 25 minutes, leaving 155 minutes, so each slot is 155 / 6 = 25.83 minutes, shown as 25 minutes 50 seconds. The second slot runs from 9:30:50 AM to 9:56:40 AM, and the sixth ends at exactly 12:00 PM.
Choosing between the two ways to split
Split by length when the slot length is fixed, such as 20 minute interviews or 30 minute appointments, and you want to know how many fit. Split by number when you need every person or topic to get the same share, such as six presenters in a three hour session.
Gaps matter more than they seem. Five minutes between ten slots adds up to 45 minutes, so a plan that looks tight without gaps may not fit once they are counted.
Using the schedule
Copy the table into an invitation, or export it as a CSV file for a spreadsheet. For a printable day plan with hourly blocks, use the daily planner. To see how long something takes from clock times, use the time duration calculator, and to count what a meeting costs in wages, try the meeting cost calculator.
Assumptions and limits
- The window must start and end on the same day. A window that crosses midnight is not supported.
- Slots are equal in length. A schedule with different lengths needs to be built by hand.
- No breaks are added at the start or the end of the window, only between slots.
- Time zones and daylight saving changes are not modeled. All times are clock times on one day.
Frequently asked questions
How do I split an hour into equal parts?
Set the window to one hour, choose number of slots, and enter how many parts you want with a gap of 0. Four parts give 15 minutes each, and a gap between parts shortens each slot to leave room for it.
What does the leftover time mean?
It is the time between the end of the last slot that fits and the end of your window. It is shown in length mode only, because equal slots in count mode always fill the window exactly.
Why do some times show seconds?
When the window cannot be divided evenly into your number of slots, each slot has a fractional number of minutes. Seconds show the exact start and end so nothing is rounded away.
Can I get the schedule in a spreadsheet?
Yes. Use the CSV button to download the slot numbers with their start and end times, then open the file in any spreadsheet program.