Date windows

This feature only applies to calendar-type timetables.

Two types: allowed or excluded

• Allowed lessons — lessons can be scheduled only during these dates.
• Excluded lessons — lessons cannot be scheduled during these dates.

How they combine

Several windows can apply to the same entity:

• allowed windows are cumulative;
• excluded windows are cumulative;
• where they overlap, an exclusion takes precedence over an authorisation.

Typical use cases

• Classes on the same work-study rhythm — several classes take certain courses only on specific weeks (or only at the beginning or end of weeks). An allowed window describing these weeks, applied to all those classes, avoids re-entering the rhythm class by class.
• Exam periods — an excluded window covering the exam session temporarily blocks the classrooms concerned, or the classes, so that no ordinary lesson is scheduled there.
• Holidays specific to certain classes — on a campus abroad, a set of classes follows a holiday calendar different from the rest of the institution. An excluded window on these dates, applied to those classes only, neutralises the period without affecting the others.

Defining a date window

On the edit screen of a calendar timetable, in the Date windows section:

1. Add opens the date picker.
2. Give it a label and choose the type — allowed or excluded.
3. Select the dates on the calendar grid: click and drag, whole week, single-day column, even / odd week shortcuts, or selection inversion.
4. Save: the window joins the timetable's reusable list.

Applying a window

Once defined, the window is available in the time constraints of classes, groups, subjects and classrooms: select one or more windows there. The same window can serve as many entities as needed — that is the whole point of the reusable overlay.

At generation

The solver treats the windows as constraints: it only places a lesson within the allowed dates, and never within the excluded dates.