See if this works for you:

A1 = Year
B1 = Day

=DATE(A1,1,B1)


"jbradford721" wrote:

I have data in Excel that has one column with the year (eg. 2005) and another
column with day of year (eg. 365 for Dec. 31). I would like to convert this
to a date format that Excel can use for calculations, graphing, etc.