Great question, it's not a typo. Making it 23 hours, it means the 'turn end' is constantly moving and never the same time of day.

The logic here is that we have players that are in Toronto Canada, Portland (Oregon) USA, Newcastle Australia and Berlin Germany. If we put the time at 24 hours, it would mean the turns are scheduled to end approximately the same time every day which introduces potential advantages / disadvantages to certain players.