Usually any month with 31 days, with the first on Mon-Tues-Weds = 23 work days.
Consultants work on a billed-hours basis, so more days at work means a bigger paycheck.
This year only JULY fits the bill - Jan, Mar, Jun, Oct, Dec are 22 day months (after holidays).
But I got an escrow check last week, pre-paid a month on the mortgage, and the credit-card game is going well (thank you FrequentMiler!) so... February?
Oh, no... wait. Marshawn didn't get the ball... worst month EVER! ;-)