The dates on which options on a particular underlying expire. The expiration day of an option is the last day the option holder (buyer) can exercise it, or otherwise it would expire worthless American options can be exercised any time before expiration date as the holder fits proper. Therefore, expiration and exercise dates can diverge. For european options, exercise can take place on expiration day. If exercised, the two sets of days converge.

In exception of LEAPS, a given option will be assigned to one of three cycles, the JAJO cycle, the FMAN cycle, and the MJSD cycle. Exchanges determine regular cycles depending on a set of factors including underlying assets, trading calendar, etc.