Not sure what the practical difference is (24/7 vs ~10/5) except for the convenience when planning data migrations if you have regularly planned downtime.

For most code changes being turned off at night isn't much of an advantage, as the new code will need to go live at some point and that point is where the risk is. For systems on 24/7 you simply need a copy of your production environment to test on, a.k.a. staging.

The main thing about 24/7 is needing follow-sun SRE and/or out of hours oncall.