The base schedule is 7 on 7 off. When you are on a 7/7 schedule you can stay on that schedule for the rest of the bidding year (10/01-09/30) unless you want to change.
The CC schedules are not set until the 15th of the month prior. For example, a pilot on a CC schedule will not know the days they will be working/off in February until the 15th of January. The number that is tied to the “CC” is the number of days you will work in the 4 month bid period. CC52 works 52 days (13 days/month average), CC 60 works 60 days (15 days/month average) CC72 (18 days/month average) CC76 (19 days/month average). On the CC schedules the company can borrow up to 2 days from a month and put them into another month of that bid period. For example, if you were on the CC72 the company can have you work 20 days in December. In return you will work 16 days in November or January.
There are 3 bid periods per year, October-January, Febuary-May and June-September.
I hope that helps.