I’m writing a non linear drama and my question is: do I have to notate what will be seen literally in the film, like age differences and such because the film won’t require much if any scene cues like “seven years later” it will all be interpreted by the viewer but do I have to notate it in the scene or action lines in my screenplay?
Think about your own audience. If you are writing a screenplay, as opposed to a novel, your intended readers are the director and cast.
As long as you have made it clear* in some fashion to the people putting on the production that the scenes fall at certain points on a timeline, your job is done. The director can take artistic license to show, not tell, the film's audience that we have moved to a different point in time by incorporating appropriate props, costumes, haircuts, wrinkles, weather, scenery, news broadcasts, etc. (or they can choose to add "Seven years later..." on the screen). Good actors will also try to portray their character as they might behave at different stages of life or being pulled along by cultural tides of slang, body language, etc.
None of that is dictated by the screenplay unless some particular detail is necessary for the dialogue/plot/actions, in which case you can include cues or notes for it (following the screenplay writing conventions you have selected).
*I believe the usual way to make the time shift clear is by including a date or similar time cue in the scene heading. This article has some tips on writing scene headings and fitting in time cues: you can include a year as part of the location name, as it is an integral part of the scene you are establishing. E.g., EXT. TIMES SQUARE (1920) - NIGHT. I think you could be as specific as necessary, but don't add more than you need to.
You may do it, you may not. Pulp Fiction didn't do it, neither Memento. When writing a small nonlinear section in my novel, I didn't do it.
However, in all of those instances there are several things that might have inspired the author not to use scene cues.
- In Pulp Fiction, there aren't many time jumps and, most of time, they are very self evident.
- In Memento, (and in my novel) the movie is intended to be confusing.
I would say the need for scene cues should be based on how many time-jumps there are (scene cues get tiring quickly), if you want the story to be confusing and if the time jumps are linear or not (Scenes A, B and C happen in the chronological order ABC, but are presented in the order BAC).