The Digital Service Providers (DSP's such as Spotify) require that content is delivered at least five (5) business days before the earliest Live Date specified in the metadata.  This is why the soonest live date you can select when uploading content is 5 business days from the date of upload. If you are submitting a new release after 5pm PST, the soonest Live Date you can select will be the following business day.

Stem FAQ

Uploading Content