Is this legal ?

Sorry for the lack of information.

He has basically worked 8 till 5 Monday to Friday, and then worked 6:00 till 8:00 on the sunday morning.
He has been asked if he can work from 20:00 till 22:00 on the Saturday.

He will work 8 till 5 again for this week Monday to Friday too.

Many thanks,

Nick.