Last week there was only one cool day.  Today one day is cool three times!

Tomorrow, 7/21/14 has all multiples of seven.  And, it is a Minus Subtract day because 7 – 21 = -14.  And finally, it is the month’s half-back day:  Go up 14 from 7 to 21, and then come half-way back (7) to 14.