You can do one or all three daily challenges every day and can go back and do any day's challenges all month. So on the 31st like today, you can do all 93 challenges that month.
Also I find the tower ones to be hit or miss. Some I've decimated to the point of having to sit around and wait several times for tiles to show up so I can keep going, but others have had the tower just shooting up with me struggling to find matches. I find the color matching ones to be the easiest and just got Supersonic (150 speed matches) on one of them. They can be crazy too when it's something like 14 rounds with only 4:30. But the speed matching ones are the bane of my existence. I don't bother unless it's 45 or lower.
Last edited by Megaseven; 11-01-2012 at 06:14 AM.