Discount possibility to change according to the set time?

[aiste.rutkauskaite]

Hello,
Is there a way we can set a discount for  15% for 72 hours and after it automatically will change for or a 10% for  another 72 hours. For example un till 12 h discount with code "April" will be 15% and after 12h 10% with the same discount code :). 
So shortly, I want that my discount would change automatically according to the set time.

[joseantgv]

You can create 2 cart rules with different "Valid from - to" dates.