Time Converter - Python Tkinter - General comments on code
One issue I can see on first glance is the *. It's considered bad practice to import everything like that, and here is why from this Stack Overflow post:


Because it puts a lot of stuff into your namespace (might shadow some other object from previous import and you won't know about it).
Because you don't know exactly what is imported and can't easily find from which module a certain thing was imported (readability).
Because you can't use cool tools like pyflakes to statically detect errors in your code.