Wrong end time suggested in availability error

[rwood-moz]

Describe the bug
When you set the availability end time so that the available time is shorter than the appointment duration settings, the resulting end time error suggests an incorrect end time.

To Reproduce
Dashboard => Scheduling Details
Verify booking duration is set to the default of 30 minutes.
Dashboard => Set General Availability
Set start time 9:00 AM, and end time 9:05AM
Click Save button

Expected behavior
Error to appear indicating invalid end time, with correct end time suggestion (i.e. at least 9:30 AM).

Actual behavior
Error appears stating end time should be at least 04:30 AM.

Screenshots

System (please complete the following information):

• OS: Mac OS 15.1.1
• Firefox 133.0 (aarch64)

Additional context
Add any other context about the problem here.

[devmount]

Yeah, this is messed up rn. We should fix this after we simplified error handling in #270 and maybe #797

What do you think @MelissaAutumn ?

[MelissaAutumn]

I think I've figured it out, will push a PR up in a min.