What are his plans for the weekend?

какой на сегодня план? перевод на английский

What's the plan for today?

какие планы на выходные? перевод на английский

What are your plans for the weekend?

What are you up to this weekend?

какие планы на вечер? перевод на английский

What are you up to this evening?

What are your plans for tonight?