The Price of Life (1987 short)
starring Jim Youngs, Dana Andersen, Diana Bellamy, Roy Brocksmith, Fred Ward, Dustin Diamond (best-known as Screech on "Saved by the Bell" TV series), Judy Geeson
IMDb review: In the future, money is not the most valuable commodity; neither are stocks nor shares. Instead, the currency of choice is time, and the populace can trade hours, days and weeks off their lives in exchange for services and goods. Into this world is born Zachary, who grows into a little boy with a game plan and a scheme to make more time; whereas his sister swaps weeks for sweets, etc., as if it doesn't matter. As adults, Zachary has continued this path, but so has his sister, and he finds himself trying to challenge the rules to try and save her and his mother. The film opens with a strange moment that becomes clearer a few seconds later when we realize that time is everything here.