It is usual to preface a description of the means of judging the age of the horse with the statement of dates, which are somewhat arbitrarily fixed as birthdays, and also to interpret certain qualifying terms which are constantly employed.

The ages of thoroughbred horses are dated from January 1st, and of other horses from May 1st. The animal which is approaching the termination of any given year is said to be "coming" the age; if the birthday has passed, he is said to be "off". Thus "coming four" is taken to mean that the horse wants about three months of the full age, and "four off" would indicate that his fourth birthday had passed about three months previously. The expert, however, will judge of a horse's age by the state of his teeth, without concerning himself about the dates which have been artificially fixed, and are indeed to a certain extent convenient.