Thanks. What if I need the multiple Date1 and Date2 for the same ID? Do I have to sort by ID, Date1, and Date2 in ascending in order to make the formula work?
Original
Data:
ID Date1 Date2
1111111 3/16/2009 6/27/2009
1111111 8/20/2009 9/10/2009
1111111 10/14/2009 11/9/2009
1111111 11/9/2009 1/11/2010
1111111 1/11/2010 (blank)
1111111 1/11/2010 1/11/2010
1111111 1/11/2010 6/9/2010
1111111 8/20/2010 9/10/2010
Final Result:
ID Date1 Date2
1111111 3/16/2009 6/27/2009
1111111 8/20/2009 9/10/2009
1111111 10/14/2009 (blank)
1111111 8/20/2010 9/10/2010
I am thinking I have to group by ID and Date1, any help? Thank you so much.