I have a set of columns with data in. I am trying to produce a list of uniqe
data based on dates from these columns. The data looks like this :

A Date
519 Sat 01 Jan
519 Sat 01 Jan
519 Sat 01 Jan
520 Sat 01 Jan
521 Sat 01 Jan
123 Sun 02 Jan
123 Sun 02 Jan
123 Sun 02 Jan
124 Sun 02 Jan
124 Sun 02 Jan
235 Mon 03 Jan
235 Mon 03 Jan
235 Mon 03 Jan

What I want to get is either the list of unique values within column a for
the date of 1st Jan which would result in 519, 520, 521 (preferable) or the
count of unique entries agaisnt the same date in this case 3.

I can extract this data using a macro, but would like the result from a
formual as the data keeps changing. I cant use filter or sort as the data is
being transferered to a seperate sheet for reporting purposes.

Thanks for any help you can provide.