Hi all,
I badly need your help in the below formula

Example:
Structure : Account includes Sub-accounts and each sub-account includes dials

Formula : Account activation date = Oldest Sub-account activation date

Column 1 Column 2
Account activation date Sub-account activation date
?? 21-01-2010
?? 26-01-2010
?? 03-02-2010
?? 14-02-2010
?? 29-04-2010

Account Activation date for the above account shall be 21-01-2010 (Oldest
sub-account activation date)

Thanks for your patience and usual support
Best regards,
Kshaheen