If I type a date in Excel, say 6/2/02 then format the cell to a number format, it will return a value of 37293 - the number of days from 1/1/1900. How do I do this in Access using a calculated field in a query based on a date in the query?

Have you tried =DateSerial([MyDate])

From the debug window:

mydate = date()
? mydate
2/6/02
? int(cdbl(mydate))
37293