Advent Calendar Planner

Filling a homemade advent calendar means spreading a list across the days without leaving a gap and without the same thing appearing twice in a row. This shuffles your list across the countdown, and when there are fewer items than days it repeats the whole set in a fresh order rather than repeating one item — so nothing comes round again until everything has had a turn.

Your items

One per line. If there are fewer than the days, the whole set repeats in a fresh order.

How many days

24 for a December calendar, or however long the countdown runs.

Seed (optional)

A word reproduces the same order, so a printed calendar can be regenerated.

Your calendar will appear here.

What this generator does

Shuffles your list and deals it out one item per day. When the countdown is longer than the list, the whole set is reshuffled and dealt again, so nothing repeats until everything has appeared.

How to use this tool

List your treats or activities, one per line.
Set how many days the countdown runs.
Read the day-by-day assignment.
Use a seed if you want the same calendar again after printing it.

Understanding the controls

Your items: One per line, up to a hundred. More items than days means some are left out; fewer means the set repeats.
How many days: Twenty-four for a December calendar, or whatever the countdown runs to. The last day is the day itself.
Seed: Reproduces the same calendar. Worth using once you have printed one and want to make another the same.

Common use cases

Filling a homemade advent calendar with your own ideas
Planning a countdown to a birthday or a holiday
Spreading a set of activities across a fortnight
Assigning a reading list across the days of a month
Regenerating the same calendar from a seed after a reprint

How this generator works

The list is shuffled and dealt out one item per day. When it runs out, the whole set is reshuffled and dealt again — which is why nothing repeats until everything has had a turn, rather than the same favourite appearing on days three and four. Before display every day is checked to have exactly one entry numbered in order, the countdown is confirmed to end on the day itself, and nothing is allowed to repeat before the full set has been used.

Randomness and fairness

Uses your browser's cryptographic random source to shuffle the list by default. A seed switches to a reproducible sequence, which is deterministic and not cryptographically secure.

For how randomness is produced across the whole site, see how Generate Random works.

Limitations and good to know

Items are treated as interchangeable, so a treat that belongs on a particular day has to be moved by hand.
Weekends and weekdays are not distinguished, so a longer activity may land on a busy day.
The final day gets whatever comes up rather than the best item, which most people will want to swap.
This assigns items to days; it does not suggest what the items should be.

Privacy and your data

Your list stays in your browser. Nothing is uploaded, stored, or included in analytics — only how many days were planned.