I'm probably just being thick, but I thought that 23 May 0:00 gmt +1 is tonight?
In other words the 22 May runs from 0:00 to 23:59 gmt +1 today and 23 May starts at 0:00 gmt +1 tonight.
Or are you working on the basis that each day starts at 0:01 and ends at 0:00, which would place the deadline at the end of Monday the 23rd?