These activity magnets give our son a visual representation of his week. They fit just about any fridge calendar. Once printed, 18mm-20mm disc magnets can be glued in place.
I've been using these:https://www.amazon.com/gp/product/B018QGZ6Z8/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
So far the set includes: