How are you going to display cutting classes am, late am, absent pm?

Besides being significantly more convoluted to code for, it'll confuse users trying to get what they want - they'll need the contradictions/exceptions explained, and it'll be more difficult to get the row and column totals correct (If the letters L, X & C in a cell all represent half days (not counting the L in the LE pair), then counting occurrences of these letters makes for simpler and more robust totals formulae.)

The 'authorities', 'powers that be', 'the higher ups', whatever, haven't put the thought into this that you (and I) have; their decisions are often ill-informed and ill-advised, sometimes they're just bloody-minded and want to show who's boss. It's up to you to advise and inform them what's best. At the moment I'm leaning strongly towards my last suggestion of the smaller triangles on top of the larger ones (If you want, we could even keep ALL cutting classes small red triangles, regardless of whether they're sittting atop another larger triangle, to maintain consistency).

I would prefer you to set things in concrete sooner rather than later - I don't want to have to revisit this too often. Remember, I'm doing this for nothing.

I think I might have to back-pedal a little on having something ready at the weekend, something's come up and it's already Friday afternoon here in the UK. Next week's very busy for me too. So you'll need patience, and I'm not giving up and I've made good progress.