I need help finding a formula that will help my find an available payment
date according to the date that someone comes in to sign a contract. Example.
Joe comes in 1/27/09. He needs to begin making payments 2 months from that
day on the next available payment day which is the 1st (4/1/09). If he comes
in on the 2/6/09 the next available payment day is tenth (4/10/09).

I want to be able to plug in a date and the next availble payment date
should pop up in another cell.

People who join anytime betweent he 26th to the 1st begin their payments on
the 1st. People who come in and join the 2nd to the 10th begin their
payments on the 10th. and so on using the 15th, 20th and 25th.

I have seen it done, but have no clue where to begin. Thanks for any help. T