Okay......

Here's a table with 1 date column, the data is......

20-Mar-2000
25-Mar-2000

I update this table to add 24 months to the date column, the data now looks like......

20-Mar-2002
25-Mar-2002

The index was

row 1 20-Mar-2000
row 2 25-Mar-2000

The index after the update should be

row 1 20-Mar-2002
row 2 25-Mar-2002

I can't make it any simpler that this...........