There are also certain days of abstinence. On days of complete abstinence (such as all Fridays), meat and soup or gravy made from meat (or anything made from meat) may not be taken at all under pain of mortal sin. On days of partial abstinence, meat (and soup or gravy made from meat) can be eaten only once. The law of abstinence must be observed by everyone age 7 and older under pain of mortal sin.
There is no obligation of fast or abstinence on a holy day of obligation, even if it falls on a Friday (such as Christmas).