Did all my 50s on the last day and was 99/100.
Kept waiting an hour and trying one more and waiting an hour and trying one more. Stuck on 99/100.
My changeover is 2am for me b/c I set it in a time zone where I didn't have competition for 1st in fleet (and also b/c it's more convenient to do fleet climb late in the evening). That's normally fine, but this time I was staying up later and later to try to get that last blueprint without spending my 100s.
Got at 1:12am with no 100s spent. That was too close. (And too late!)