In Excel, the 'YEAR()' function within a formula extracts the year part from a date. However, we don't have valid dates, in column B we have a 'sortof' date as a year and month ('2008-04'). We can write a formula that will convert that data into a full date (e.g. '2008-04-01'), and then extract the year. In the first data row of your new column enter the formula: =YEAR(CONCATENATE(B2,"-01"))