I've booked tickets to watch FC Barcelona play Atletic Club Bilbao, currently scheduled for Sunday 18th March, 2018. Since the date and time won't generally be confirmed until about 2 weeks prior to this date, I'm wondering whether there is any chance this game would be rearranged for a different weekend?

Would it be moved to a different weekend to cater to cup matches, for example? Or if I booked to stay in Barcelona (Flying from the UK) from Friday 16th until Tuesday 20th, would the match definitely be within this period and make it safe to book now whilst prices are low?