You could modify the circular reference formula at

http://www.mcgimpsey.com/excel/timestamp.html

to substitute your conditional statement for A1="".

Or you could use something like the event macro shown there, but using
the Calculation event instead, for instance:

Private Sub Worksheet_Calculate()
Dim rCheck As Range
Dim rCell As Range
On Error Resume Next
Set rCheck = Range("A:A").SpecialCells(xlCellTypeBlanks)
On Error GoTo 0
If Not rCheck Is Nothing Then
For Each rCell In rCheck
With rCell
If .Offset(0, 1) = True And .Offset(0, 2) 10 Then
.NumberFormat = "mm/dd/yyyy"
.Value = Date
End If
End With
Next rCell
End If
End Sub

Modify to suit your conditions.

In article ,
"Dan Morton" wrote:

Would like a date entered in a column the first time a condition is met
calculated on several other columns in the same row. How could this be
implemented?