Why ek ghante instead of ek ghanta?
'एक घंटा' is in the oblique case because of the postposition से. The oblique case form of घंटा is घंटे.
What is " Oblique case"
In Hindi, certain words change form when they are objects of a postposition. This is called the oblique case. I've written some more about it here. You can also go through the Duolingo tips section on the oblique case here
Looks like my schedule
How can one see in Hindi the difference between 'He has been eating for an hour', and: 'He has been eating snce an hour'?
फिर मैं फट गया! हा हा हा हा!
Of course duh