Preparation day of 23 hours
As many clans out there, our clan wants to have a war continuously, but every next war starts about 1 hour later even if we start immediately after the previous one finishes. This makes us skip a day once the start of war shifts well into night...
So it would be supercool if the preparation day is shortened a bit, to 23 hours, so we can start (and finish) every war at approximately same time of day.
P.S. 23 hours is still good enough for round-the-globe clans to have plenty of opportunities to donate troops.