Asked by: Richard O'Neill, Glasgow
International Space Station crews experience a sunset or a sunrise every 45 minutes. New members arrive acclimatised to Kazakhstan time, having departed from the Baikonur Cosmodrome. With so much scope for chronological confusion, it’s no wonder that the ISS needs to be locked to a consistent time. The zone of choice is Coordinated Universal Time (UTC), which is equivalent to GMT.
Image credit: NASA