The following entered in Col B of Arenas will give you 1 if the name in Col A
matches
with a name in Chart1:colE
=ISNA(VLOOKUP(A1,Charts!E:E,1,False),0,1)

I did not understand your reference to E4...

I don't think this is what you want... Let us know
"bob" wrote:

The worksheet "Arenas" contains a list of names in colA. The worksheet
"Chart1" contains a list of dates in colA and a list of names in colE.

From the Arenas worksheet, I want to populate cell E4 with a value of 1 for
when a name in Arenas:colA matches a name in Chart1:colE and has a unique
date in Chart1:colA. If there are multple matches for a given date, I still
want cell E4 to have a value of 1 (instead of the number of times a match
occurs for that date). If no matches exist, E4 should have a value of 0.

Can anyone kindly help? Thank you.

Bob