>>No, because GOMONTH stays within the same month. There is no February 29, 2001, so it HAS TO return the last available day for that month, the 28th.
>
>That's interesting. Now, a special logic need to be applied here. Because, if I use that, the result would be to offer an expiration date which contains a day less than others who took their membership elsewhere in the year.

Well you could always do GOMONTH(date,12) + 1. That would be one extra day, in all cases, but if you signed up on the last day of a month, your expiration would be the 1st of the next month.