The plan

Almost everything in ontoplano is one of four things. They are easy to confuse from the schema, because three of them are rows about "a thing at a time", and the difference between them is what happens tomorrow.

A weekly block

weekly_slots. Tuesday at 09:00, every week, for an hour. It is a shape of the week rather than an event: it has a weekday and a time and no date at all.

Editing one changes every week — past weeks included, because there is no copy of it in any of them. That is the point of it, and it is also the trap: "move the gym to Thursday" is a different act from "I went on Thursday this week", and the second must never be done by editing the block.

A one-off block

exceptional_slots. The 4th of September at 09:00, once. Same fields, plus a date instead of a weekday. Nothing about next week follows from it.

This is what a todo becomes when it is given a time, and what a weekly block becomes for one day when you drag that day's occurrence somewhere else while holding Alt — the occurrence detaches into a one-off and the weekly block goes on repeating, untouched.

An occurrence

task_instances. What actually happened on one day. It is the row that carries a status (todo, doing, done, skipped), when it was done, notes, and whether it was early or late.

An occurrence points at either a weekly block or a one-off block, never both. For weekly blocks they are generated ahead — one per week per block — which is what makes it possible to tick off Tuesday's gym without saying anything about next Tuesday's. Everything the tracker, the history page and the goals count is occurrences; the blocks are only their reason for existing.

Skipping one day of a weekly block does not touch the block either: it writes a suppression for that date, and the grid draws it as skipped.

A todo

planner_todos. A task with no time yet. It has a title, notes, a category, a notebook, three ratings — and a nullable scheduled_date.

That one nullable column is the whole distinction people trip over:

• scheduled_date is null — it is in the general list. The board's backlog, and the strip beside the planner grid.
• scheduled_date is a date — it has been pulled onto that day's board. It is on that day, but it still has no hour, so it is not on the grid.

Neither of those is a block, and neither has an occurrence. A todo left on Monday and not finished follows you forward: the board and the planner strip both keep showing it after its day has passed, because a task you did not do has not stopped needing doing.

Becoming one another

The moves that matter are the ones that change which of the four things a row is. All of them move the row rather than copying it, so the same task is never on screen twice.

Scheduling a todo keeps what a block can hold — the name becomes the label, the notes ride on the occurrence, the category, notebook and ratings come across — and taking it back off returns the same things. What is lost going back is the date and the hour, which is exactly what was being given up.