From your shooting time, interval and playback frame rate, work out how many frames you will shoot, how long the final clip runs, and the storage needed.
A time-lapse takes one frame every interval, then plays them back at the clip frame rate. Frames = shooting time / interval, and clip length = frames / fps. Storage is a rough estimate based on an average file size.
Frames = shooting time divided by the interval, then clip length = frames divided by the playback frame rate. Shooting for 60 minutes at a 5-second interval gives 720 frames, which is 30 seconds at 24fps.
Shorter intervals (1-3s) suit fast subjects like traffic and people; longer intervals (15-30s) suit clouds and sunsets; very long intervals (minutes) suit plants and construction. Shorter intervals mean smoother motion but more frames and storage.
It multiplies the number of frames by an average file size you provide. Raw files are larger (often 20-40MB) than JPEGs (often 3-8MB), so set the figure to match how you shoot.