Q1
I have inherited a spreadsheet that has the date split over 3 columns: -
a1 = day
b1 = month
c1 = year

How can I put these in one column to read dd/mm/yyy

Q2

How can I work out the day number of a particular date?

Ie 28/10/2004 = 302


I also need to take into consideration the leap years accordingly

TIA