I have spent ages trying to google a solution to this and have come up with nothing, though it seems that it should be quite simple.

I would like to create a formula to do the following:

Take the value from cell a
Add the value from cell b to cell a each month on a specified date (i.e 6th of each month ongoing)
and
Add the value from cell c to cell a each month on a specified date (ie 1st of each month ongoing)
and display in cell d

I thought that I could use the if and today functions for this but I'm clueless as to how to get excel the pick out the 1st or 6th of a month.

Any help at all would be very much appreciated.