Simple Timed Stasis Chamber (extendable to any number of days)

Have a chest into a hopper into a dispenser. Fill the dispenser and hopper with non-stackable items (for example, water bottles).

Have a Daylight detector on top of the dispenser so it only dispenses 1 water bottle per day and the chest will drop by 1 bottle per day also.

Have a comparator read the output of the chest straight into the trapdoor. When the chest is empty the trap door will close.

You could also do this with a large chest and you could also have additional chests filtering into this one with hoppers to extend it basically forever.

You could also fill everything with the same stackable item, but you'd need 896 items instead of just 14 to fill the hopper and dispenser.