Here's one way, I assume you have sorted by first PN and then the dates (and
times) ascending, try this instead. Sort by PN ascending and Date No
descending, will give you this instead

PN              Date No
007-0566     37735.29
007-0566     37595.21
007-0567     37735.29
007-0567     37595.21
007-0569     37995.36
007-0569     37553.19
007-0569     37522.25
007-0570     37995.36
007-0570     37553.19
007-0570     37522.25
007-0572     37995.36
007-0572     37522.24
007-0576     37995.36
007-0577     37522.24
007-0581     37593.48

this means that the first occurrence of the PN will also have the latest
revision, assume the data (not the headers) start in A2 with the dates in
B2, in C2 put

=COUNTIF($A$2:A2,A2)

copy down 35000 rows by select C2 again and move the cursor to the lower
right corner of C2 and when the cursor changes to a thick cross double click
to copy down the formula.

Now select the whole table from A1 to C35000, you can do that by typing A1:C
35000 in the namebox above the column A header and pressing enter. Then do
data>filter>autofilter,

from the dropdown in C1 select 1, now select the visible range and copy and
paste it unto a new worksheet. Finally remove the help column and format as
date and time

I did a little test on your sample and it returned exactly the result you
posted

You can also do this using advanced filter, there you can actually copy the
filtered list directly somewhere else

Steve,

You can do it in two steps:
assuming the parts are in column A and dates are in column B

1. create a third column with the following array formula
=IF(MAX((RangeOfPartNumbers=$A1)*(RangeOfDates))=$B1,1,0)
This column will be flagged as 1 wherever the max date occurs for each
part number

2. Advance filter the third column for 1, that's your condensed list

Just another option, you can do it with a Macro:

Sub StripIt()
   Dim LastRow As Long
   Dim x As Long

   LastRow = Cells(Rows.Count, 1).End(xlUp).Row

   With Range(Cells(1, 1), Cells(LastRow, 2))
       .Sort Key1:=Range("A2"), Order1:=xlAscending, Key2:=Range("B2") _
       , Order2:=xlDescending, Header:=xlGuess, OrderCustom:=1, MatchCase:=
_
       False, Orientation:=xlTopToBottom
   End With

   Application.ScreenUpdating = False
   For x = LastRow To 3 Step -1
       If Cells(x, 1).Value = Cells(x - 1, 1).Value Then
           Range(Cells(x, 1), Cells(x, 2)).Delete Shift:=xlUp
       End If
   Next x
   Application.ScreenUpdating = True

End Sub

It assumes that the Headers are in A1:B1.

Try it on a *copy* of your data