Scheduling Constraints

Everything that can produce an inbox task also carries a small set of scheduling constraints - what Thrive should assume when it tries to put that work in the calendar, and how much of your time it takes up in a time plan.

The entities that carry them are the ones that own inbox tasks: todos, habits, chores, big plans, metrics, persons, occasions, Slack and email tasks, and the settings behind journal writing tasks, time plan planning tasks, working mem cleanup tasks, and life plan eval tasks.

Schedulability

The first constraint is whether the work can be scheduled at all:

• Schedulable: the work takes real time, and a block for it can be placed in the calendar. "Buy groceries" is schedulable.
• Not Schedulable: there is nothing to place. A habit like "no sweets today" is something you keep to over the whole day, not something you sit down and do, so it never becomes a calendar block.

Everything is schedulable unless you say otherwise.

Time Hints

Anything schedulable takes up real time, so it always says how much:

• The event duration, in minutes: how long one block for it should be.
• The event count: how many blocks are needed, at least one.

Both are required of anything schedulable - there is no "unset" to fall back from. Something new gets one block, as long as its difficulty suggests - 15 minutes for easy, 30 for medium, 60 for hard - until you say otherwise. Change the difficulty on a creation form and the duration follows along, until you pick one yourself.

Work with no difficulty of its own - an occasion, a working mem cleanup - counts as easy. Work whose difficulty isn't set at all, like a person with no catch up, gets the medium half hour.

A habit of "three half-hour runs a week" is an event duration of 30 and an event count of 3.

Something that isn't schedulable carries neither.

What They Change

Scheduling constraints are read in two places.

When you place a time plan activity in the calendar, the block starts out at the event duration of whatever the activity points at. An activity that isn't schedulable can't be placed at all. Where nothing carrying scheduling params is involved, the duration is inferred from the task's difficulty in the same way.

When a time plan works out its load - the hours and activities it adds up to - activities whose entity isn't schedulable are left out entirely, and the rest count for their event duration times their event count. So a week full of "no sweets today" doesn't look like a week with no room left in it, and a habit that needs three half-hour runs asks for the hour and a half it really needs.

An inbox task takes after whatever generated it, so a task generated by a habit that isn't schedulable isn't schedulable either. A habit or chore stack can be scheduled as long as one of its members can be.