Most people believe that NFL officiating is just a three-hour job every Sunday; well they are truly wrong. The following is a general list of tasks officials goes through during the week to prepare for their upcoming game.
The number of hours an official spends getting prepared for a game, depends on their position.
All officials study video of games that they break down and study at all angles. This studying varies from 15-20 hours or more per week.
The officials spend a few hours on the phone. During this time, they communicate with crewmates and discuss certain calls, game situations and rules interpretations.
Each official is required to take a written test every week during the regular season. All officials also must submit a monthly test during the off-season. These tests are not graded. The purpose for the tests is to keep the officials "fresh" with the rules. Most officials spend at least 1 to 2 hours or more a week studying the rules and casebooks.
Every official must also keep in shape during the regular season and off-season. Physical conditioning is a major factor in officiating. This could take 2 to 3 hours every night or even longer in some cases.
The Referee's (Crew Chief's) must submit game reports to the league office and write letters.
Officials are given random drug and alcohol tests that could occur at any time during the season. This usually happens around two times a season.
Most officials leave for their game late Friday night or early Saturday morning. When they arrive in the city of their game, they attend a meeting with the rest of their crew in which they review more game tapes and review rules tests. On the Sunday of their game, the officials conduct a pre-game meeting which outlines the entire game for them.
So depending on which position you work in the league, all NFL officials roughly spend at least 30-40 hours a week getting prepared for their upcoming game and at the same time they are working other full time positions in their regular life.