In a script, if a scene goes from one day of the story to the next day (NIGHT then DAY), we call that a change in the Dramatic Day. Sometimes called "Script Days" or "Story Days" these help keep track of what day within your story events happen on.
Dramatic day can affect everything from costuming, the makeup to sets and more. You do want your characters to change clothes sometimes right?
Within the Breakdown, you can add a dramatic day to each scene. Standard practice is to start at 1 and move forward. Flashbacks might have a separate day altogether (something like 99 to set it apart).
Sorting your Schedule by Dramatic Day
These dramatic days can then be used in your Schedule to sort your scenes. Click on the column heading "Dramatic Day" and it will sort ascending or descending.