In colleges on the quarter system (at least the one I attended some thirty years ago), three quarters made a whole! (Sort of like .999... equals one?) Actually there was a fourth quarter but that was the summer session and not part of the regular school year. The first quarter ended just before the Christmas holiday which was in a way better than the semester system at that time which involved taking the winter break and then returning almost directly into Finals. Presumably credits for a quarter equated to 2/3 of those for a semsester.

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Cum catapultae proscribeantur tum soli proscripti catapultas habeant.