I wouldn't have expected that you'd need (or want) a CDate conversion of what
Max returns, as it should already be a date.

What happens if you remove it?

I added the CDate function so the variable would display as a date
(say, 01/05/2005) in the msgbox. If i remove it they just display
the date  as a number (38473). Either way, the max  and min  is
returning the same value and not distinguising between the dates.

For example, I know that the earliest date in the named  range is
01/05/2004 and the most recent is 03/02/2006. Using the code
originally posted, both Max and Min return  the 01/05/2004 date. If i
remove the CDate they both return 38108.

If i do the same thing on the worksheet rather than use VBA they
behave as expected, which is why i can't figure out why the VBA
fails to tell the difference.

Okay, after a bit more tinkering, I think i know what's happening,
but i've no idea why or how to correct it.

Application.WorksheetFunction.Max or Application.WorksheetFunction.
Min seem to be evaluating the entire named  range but are returning
the value of the first cell in the range  not the value of the cell
that corresponds to the actual max  or min. Don't know if this sheds
any light on what's happening.

I created a myDATES range  with several thousand dates, and your unmodified code
works perfectly for me. It sounds like Min and Max are only looking at the first
cell in your range. If the name is defined via VBA, maybe it's not including all
the cells you think it is. If this is part of a longer procedure, maybe the name
is being re-assigned to the single cell somewhere, before you are calling Min &
Max. Why not stick a statement like

MsgBox Range("myDATES").Address

just before your Min/Max calls, to see what cells are included in the search
range?

Not been following this but does sorting the named  range help?

Sorting the named  range doesn't affect min  & Max, as it might affect a Vlookup.
I sorted the myDATES range  I created in ascending, descending, and random
orders, and got the right answers every time.