Is there a way for my iphone itself at 4pm?

So I can force myself to do chores? And that I can unlock when I'm done?

Nope, iOS doesn't not allow it.

Android does but that sounds like an app that has yet to be written.

Nope, not a regular iPhone. There *are* parental controls but they don't include time-based control.

Maybe there's something like this for jailbroken phones, but I'm not sure.