Why does iTunes Connect say that the day isn't over yet in all regions when it is?
No, this is not due to a lag or bug. The fact is that as I write this, it is still 30 June 2017 in some regions. 

For example, right now it is 10:27pm Friday night in New York.

[EDIT]

You may find it useful to refer to one of the many online time services, such as the World Clock to check what the time is at any given moment around thew world.