The school year is divided into two terms: the Winter term (September–January) and the Summer term (March–July), with a month's holiday between them. Students starts at Cackle's at the age of 12, and finish at the age of 17, for a total of five school years. The students arrive at the start of the term by flying broomsticks, except for the new first years, who walk through walker's gate as they can't fly yet. Halfway through the first term, the first years are each presented with a black kitten - Mildred receives a grey-and-black tabby cat as they apparently ran out of purely black cats - which they teach to ride the broomstick. The first book postulates that the cats weren't for any practical purpose except to keep tradition going, and in "Wishing Star", a group of elder witches note that there is no restriction on what animal a witch must have as her flight companion, with cats only being traditional as they are discreet and easy to care for, which leads to Mildred being permitted to fly with her dog, Star, after he shows greater broom aptitude than her cat Tabby. At the end of the first year, each pupil receives a copy of "The Popular Book of Spells", a three-inch thick volume bound in black leather. This was not really to be used, as they already had paperback editions for the classroom, but like the cats, it's another piece of tradition. At the end of the fifth and final year, students sit the exams for the W.H.C. (Witches' Higher Certificate), and most pupils were awarded with the certificate.