Usually it is the first Friday of the month, which sometimes it can be on the 1st or 2nd of the month (e.g. 2-Dec-11, 1-Apr-2011), but other times it is delayed a week to the 2nd Friday (8-Jul-11, and next week’s release rather than 2-Mar-12).
Answer from the Current Employment Statistics (CES) program:
The Employment Situation report is released on the third Friday after the conclusion of the reference week, i.e., the week which includes the 12th of the month. CES requires this time to ensure adequate collection of sample reports and sufficient time to produce estimates. February 18 was the end of the February reference week, and March 9th is the third Friday following the reference week. Press release dates are published online at http://www.bls.gov/ces/ces_tabl.htm.