A teacher cannot make it — who arranges the substitute?

The teacher reports it from their phone, the admin decides. From that report the admin can appoint a substitute teacher for the session or cancel it; teachers never call off a class unilaterally.

The substitute sees the session in their own schedule and can fill in its attendance. If the session is canceled instead, it follows the holiday path: no pack is deducted and parents are informed. A teacher can also withdraw their report while it is still undecided, and the decision is sent back to them.