How to put downtime on EE Hawk phone?

[Grandadwasthatyou]

Well seeing as my 14 year old ds has now managed to break 2 iPhones ( not brand new but ones which had been passed down to him) I am unwilling to give him another one.
A relative has found an EE Hawk phone which they never used and have said he can have.
I would like to put downtime on it so that it cannot be used between certain times. I know how to do it on an iPhone but haven't a clue with this. I have googled and cannot find anything relevant.
Is anybody able to help please?