Count if statement

[Alaska1]

I need to get the minimum date for the customer id in the attached file a
and tag it as the a number on in the file in the file. Can I use a count if statement?

[Alansidman]

In C2 type =INDEX($A$2:$A$7,MATCH(B2,$B$2:$B$7,0),MATCH(MIN($ A$2:$A$7),$A$2:$A$7,0)) and copy down.

[Alaska1]

Thank you for your response. Not sure what happen to my question below. I need to put the number one in the minimum date for that customer id.

example
4/3/2019 23456 1
6/1/2019 23456 0
9/1/2019 23456 0
4/20/2018 34567 1
10/1/2018 34567 0
5/3/2019 34567 0

[p45cal]

C2:
=IF(MINIFS($A$2:$A$7,$B$2:$B$7,B2)=A2,1,0)
copied down.

[Alaska1]

Thank you for you help.

[ArviLaanemets]

Another way (you can hide column CustRow on sheet Data).

In case there may be several entries for same customer at same date, the formula will not work!

[Alaska1]

Thank you for all your help.