Rotation Calendar Builder

A free browser tool

Which day is it? Every date, lettered.

The rotation advances only on days school is actually open, so no letter can be read off a weekday and one snow day re-letters the rest of the year. Give this your term, your closures, and your cycle, and every date gets its letter. No account, and nothing leaves this tab.

Step 1

The term and the cycle

Days the school is in session

One per line. A range is 2026-12-21..2027-01-01 Winter break. These pause the rotation; they do not skip a letter.

Assemblies, testing weeks, half days. Optional, and the one case a closure cannot express.

Optional. Whatever you write here is printed under the letter on the calendar and on the door cards.

How it works

The term is walked date by date, because that is the only way

  1. Every date from the first day to the last is visited in order. A weekend, a closure, or a day you marked as standing still gets no letter and does not move the cycle on.
  2. Every other day takes the next letter. That is the whole rule, and it is why one lost day in November changes every letter after it.
  3. You get a month-by-month wall calendar, an index listing every date each cycle day falls on with how many times it comes up, and a card per cycle day for the classroom door.

FAQ

Before you use it

What happens to the rotation on a snow day?

Nothing is skipped. The sequence advances only on days students attend, so if you were due a Day 3 and the school shuts, Day 3 happens when everyone comes back and everything after it moves along by one. Put the day in the closures box and rebuild; the whole remainder is re-lettered for you.

What if school is open but the cycle does not move?

That is a real case a closure cannot express, so it has its own box. An assembly day, a testing week, or a half day is attended and still carries no letter. Those days are shaded differently on the calendar and counted separately in the summary.

Why does one cycle day come up fewer times than another?

Because holidays are not evenly spread. Over a year an unlucky cycle day can land on several closures and come up three sessions short of the best-served one. The summary says which days are short and by how much, which is the thing a blank template can never tell you and the thing a specials teacher most needs to know in September rather than in May.

Does it have to be A and B?

No. There are presets for A/B, A/B/C, a six-day letter cycle, and Day 1 to Day 6 or 7, and you can type your own in any labels you like. Some schools run colours, some run periods. The cycle is just a list that repeats.

Our week is not Monday to Friday.

Untick the days you do not run. A four-day week or a school that meets on a Saturday still rotates correctly, because the cycle counts attendance days rather than weekdays.

Can I give it to parents?

The month grids are the page most schools publish, and they print as a plain PDF with no account and no watermark. The door cards are four to a sheet and say which cycle day it is, what meets, and the next four dates it comes round.

Is this free?

Yes. This validation version has no payment or account.

Is what I type stored?

No. The calendar is worked out and drawn in this tab. Anonymous usage events and feedback are recorded.

Privacy

We record anonymous interaction events, a random browser session identifier, referral source, device category, and feedback. We do not intentionally collect names, email addresses, IP addresses, or the text entered into the tool.

Terms

This experimental tool is provided as-is. Check the calendar against your school's own published dates before relying on it.