Rules of Fast
The laws of fast apply to persons between the ages of twenty-one and fifty-nine. On a fast day one may eat one full meal and two light meatless meals, which together would not equal the main meal. Meat may be taken at the principal meal, except on days of complete abstinence. Liquids such as water, milk, and fruit juices may be taken between meals.
Rules of Abstinence
The laws of abstinence apply to everyone seven years of age and over. On a day of complete abstinence no meat, meat gravy or soup made from meat may be taken. On a day of partial abstinence meat may be taken once.
Traditional Days of Fast
All the days of Lent up till noon on Holy Saturday, Ember Days, the Vigils of Pentecost, the Immaculate Conception, Christmas, and All Saints.
Traditional Days of Complete Abstinence
Every Friday of the year, Ash Wednesday, Holy Saturday (until noon), the Vigils of All Saints, the Immaculate Conception, and Christmas.
Traditional Days of Partial Abstinence
Ember Wednesdays and Saturdays and the Vigil of Pentecost
Local Custom in the USA
In many places in the United States before Vatican II, it was customary to dispense from the fast on St. Patrick’s Day (March 17) and from abstinence on the Friday following Thanksgiving.