Not really. Space has generally been pretty good with 50 minute episodes in the past at either fitting them into the hour timeslot or allowing them to ten to fifteen minutes over. Thankfully, Doctor Who airs on Saturdays, which Space usually airs movies and they rarely every fit into the perfect timeslot mold.The Christmas episodes are 60 minutes and have a 90 minute timeslot. The 50 minute episodes will just be awkward.