Since I began paying quarterly estimated tax payments, it has always bothered me that the due dates aren't 3 months apart. Quarter 1 (Q1) taxes are due April 15, 15 days after Q1 is over. Q2 taxes are due June 15, only 2 months after Q1 taxes, and 15 days before the Q2 is over. Q3 taxes are due September 15, 3 months after Q2 taxes, and 15 days before Q3 is over. Q4 taxes are due January 15, 4 months after Q3 taxes, and 15 days after Q4 is over. So, Q1 is 3 months, Q2 is 2 months, Q3 is 3 months, and Q4 is 4 months. Why not have the taxes always due 15 days after the quarter is over (April 15, July 15, October 15, and January 15)? Anyone know what the reasoning behind this is? Do they just want your money early two months to make up for it being late two other months?