converting dates to numbers and numbers to dates

I am going crazy here. I am looking at a code, and basically there was a cell that looks like this:
traindate ---- 2005/12/21 and they converted this to a number simply by going traindate = ActiveCell
and traindate=right(traindate, 10)
and then they pasted this in a random cell and changed the cell format to general and bada bing we have a number. Now I want to know how to do this manually. If i type a date into a cell and then convert to general i still only have a date. How in the world do you do this, and why did it work in his case. If i type a number into a cell and click format date, then i get a date from the number, but not the other way around for some reason????
thanks

i would like to do the same thing. I have some fields that i would like to format with a for loop. I have
For iDate = 1 to NumOfDates
Sheets("requests").Cells(4, tDate * 2 + 1).Value = Format(StartDate + Format(tDate, "d"), "d-mmm")
Next

i know formatting an integer doesnt change its data type but i hope you can see my drift.