Fixed first, then proportional
Any agenda mixes two kinds of item. Some have a length that is decided elsewhere: questions get ten minutes, the break is fifteen, the demo takes as long as the demo takes. Others just need to fill what is left, in roughly the proportions you have in mind.
Write "min" after the number and the item is fixed at that length. Write a bare number and it is a weight. Fixed lengths and inter-item gaps come off the total first, and everything remaining is divided among the weighted items in proportion to their numbers.
Weights are relative only. Writing 1, 2, 3 gives exactly the same result as 10, 20, 30. All you are encoding is "this section should get about twice what that one gets", which is usually the only thing you actually know at the point where you are planning.
Rounding, and the minute that has to go somewhere
Proportional division produces fractions. Twenty minutes across three items weighted 1, 2 and 3 gives 3.33, 6.67 and 10. Rounding each to whole minutes gives 3, 7 and 10, which is twenty — this time. Often it is not, and rounding to five-minute steps makes the mismatch worse.
Rather than leave the table not adding up, the leftover is pushed into the longest weighted item and marked in that row. It is the item where a minute either way is least noticeable. If you want the exact proportional split with no adjustment, leave the step at one minute.
Five- and ten-minute steps are worth the imprecision when a person has to run the session from a clock. "Ends at 2:35" is followable; "ends at 2:33" is not.
Gaps are not padding
The gap field adds a fixed amount between items and takes it out of the pool before dividing. It is for the things that happen between agenda items but are not agenda items: swapping presenters, reconnecting a screen share, letting people finish a sentence.
One minute between items sounds trivial. On a six-item agenda it is five minutes, which is a whole discussion topic. Building it in explicitly is why the printed plan and the actual meeting stay close to each other.
Clock times make it usable while it is happening
A column of durations is a plan. A column of clock times is something you can check against your watch without arithmetic. Add a start time and every item gets a real start and end, in twelve-hour form by default with a switch for twenty-four. Anything running past midnight is marked with a day offset rather than wrapping silently.
In practice you do not track every row. Memorise one — usually the end of the opening section, since that is where overruns start — and correct from there.
When it says you are over
If the fixed items and gaps already exceed the total, there is nothing to divide and the page says so instead of producing a table of zeros. This is worth taking seriously at the planning stage, because on the day it does not present as an overrun spread evenly across the session. It presents as the last item being cut entirely, and the last item is usually the conclusion.
Related pages
To add up durations rather than divide one, use the Time Calculator. If the thing you are dividing is a deadline rather than a session, the Deadline Backward Schedule walks stages backward from a due date across working days instead.
Questions people ask
Can I mix fixed items and weights in one list?
That is the intended use. Fix the parts whose length is already decided, weight the rest, and the remainder is divided among the weighted items only.
What happens to an item with no number?
It is treated as weight 1, so it gets an equal share alongside any other weight-1 items. A count of such lines is reported under the table so you can tell it was a default rather than a choice.
Why does one row say "rounding +2m"?
Rounded allocations rarely add up to the total exactly. The difference is put into the longest weighted item and labelled, so the column still sums to the time you actually have.
Does it handle a session that runs past midnight?
Yes. Clock times past midnight are shown with a day offset rather than wrapping back to the morning, so a session starting at 11:00 PM reads correctly.