Somebody was asking about the DAL-N paychecks, here is an excerpt from the company:

How will this transition impact me?
For the month of January 2010, instead of receiving a paycheck on January 13th, you will receive your check on January 15th for your December settlement. The check you receive on January 31st will be your advance payment for January.

Now, my question is how can you call a paycheck on the 31st, for work already done, an "advance"???