Thank you Dave and Nick for your help and time. I don’t know if this might be of interest to members, I also got this help from another generous soul who told me to Just use the formula

=MIN(OFFSET($C$2,(INT((ROW(A2)+8)/10)-1)*10,0,10,1))

in C2, and copy down. It worked as-is, but I decided to prefix it with an IF statement to take care of empty date cells. So the resulting formula I pasted into C@ was

=IF(C2="","",(MIN(OFFSET($C$2,(INT((ROW(A2)+8)/10)-1)*10,0,10,1))))

Once again thanks, very much appreciated and keep up the good work.

Koby

sort ur data by:

'Project ID number'
then
'Project start date' ascending..

then use vlookup on 'Project ID number' returning the 'Project start date' col..

no need to adjust the formula...

Alternatively, and a much better solution is to
- select all your data
- insert a pivot table
- choose 'Project ID number' as the row field
- choose Min Of 'Project start date' as the data field

then u get this:

Row Labels Min of Project start date
TX001 28-Aug-06
TX002 06-Oct-04
TX003 01-Mar-05
TX004 01-Jan-05
TX005 06-Oct-04
TX006 01-Jun-05
TX007 01-Mar-05
TX008 01-Mar-05
TX009 01-Jun-05
TX010 01-Apr-05

I'm guessing that using the subtotals tool in the spreadsheet isn't what you're after...?

Paste the following code into a UDF (To set up a UDF follow instructions here: http://www.wikihow.com/Create-a-User-Defined-Function-in-Microsoft-Excel)

Option Explicit

Public Function minDate()

Application.volatile

Dim startRow As Integer
Dim endRow As Integer
Dim caller_r As Integer
Dim r As Integer
Dim projID As String
Dim locDate As Date

caller_r = Application.Caller.Row
r = caller_r
projID = Cells(r, 1).Value
locDate = Cells(r, 3).Value
Do Until Cells(r, 1).Value <> projID
startRow = r
r = r - 1
Loop
r = caller_r
Do Until Cells(r, 1).Value <> projID
endRow = r
r = r + 1
Loop

For r = startRow To endRow
If DateDiff("d", locDate, Cells(r, 3).Value) <= 0 Then locDate = Cells(r, 3).Value
Next r

minDate = locDate

End Function

A couple of things you should be aware of.
1) This UDF does not take an input parameter. Just call it as "=minDate()" in your spreadsheet. It does assume, however, that your data is ordered as in your example, that the project titles are in column 1 and the dates in column 3.
2) I walk up and down from the row you call the function from to determine the "boundaries" of the project code, and then iterate from the minimum row to the maximum row to determine the lowest date. If there are "holes" in your first column, the rows will be bounded by those holes.
3) This will produce the date in whatever format your output column is set up to. If it is as "general" then you will get an Integer, so just make sure you reformat your cells to the date format that suits you.
4) Recalculating UDFs when inputs change is a bit of a dark art IMHO. This one should recalculate (note the application.volatile line), provided you have set calculation to automatic in excel.

Frankly, I would not use a UDF for this but rather write a macro that would do the same thing by walking the entire sheet, and that I could call by pressing a button. But that's probably because I have an unjustified aversion to UDFs and tend to do everything in macros anyway...

Hope this helps,

Dave