Good morning, @Sam142 and @larirg! I'm glad to see you both in the Community with this question. I'm happy to explain your options with QuickBooks Time and these notifications, 

If you use the schedule in QuickBooks Time, you're able to set up alerts for when employees clock in early or late to that shift. There's also a schedule report called "Tardies" that will give you the amount of times an employee was late clocking into their shift. 

As far as being able to limit the time users can clock in, that's not available in QuickBooks Time right now. I'd definitely recommend reaching out to our developers and requesting this feature. It's really important for us to know what would make our customers' business run smoother and how we can improve.

Here's an article walking you through how to leave that feedback: Submit feedback to QuickBooks Time.

Please feel free to reply to this post with any questions you may have. All of us here in the Community are eager and happy to help!