The Day Out of Days[1] is a chart used by producers of motion picture entertainment in the USA to tally the number of paid days for each cast member.
The chart must be prepared after the shooting schedule.
Once it has been completed, work can begin on a budget.
The letters S (Start) and F (Finish) are used to indicate the first and last paid days.
(The rules do not apply for actors with "run-of-show" agreements.)