Not sure how much "validation" you want to do on what is entered, but this
asks for a date (and puts in the current date as the default date in the
input box), then inserts the user response into E15 and formats. If you
don't want a default date in the input box, then where it says "USERENTRY =
InputBox...", remove the Format(Now, "mm/dd/yyyy") part of that line. Also,
you can change how you want the date formatted by changing, for example,
mm/dd/yyyy to mm/dd/yy. If you want more "validation" that this, then one of
the more experienced folks will have to help. Hope this is useful.

Sub AskForDate()
Dim MSG As String
Dim USERENTRY As String
Dim DATEVALUE As Boolean

If Worksheets("Input and P&L").Range("E15").Value = "" Then
DATEVALUE = IsDate(USERENTRY)
MSG = "There is no date in the 'Date Prepared' field on the Input and
P&L tab. If you want to use the current date, then just click on 'OK'. If
not, enter another date below (in mm/dd/yyyy or m/d/yy format), then click on
'OK'."

Do
USERENTRY = InputBox(MSG, "PLEASE ENTER THE 'DATE PREPARED'",
Format(Now, "mm/dd/yyyy"))
If USERENTRY = "" Then
MsgBox ("You must enter a response; please try again.")
End If
If IsDate(USERENTRY) = True Then
Exit Do
End If
Loop
Worksheets("Input and P&L").Range("E15").Value = USERENTRY
Worksheets("Input and P&L").Range("E15").NumberFormat = "mm/dd/yyyy;@"
End Sub

"a m spock" wrote:

I have a macro working which populates a table with user data entry with
input prompts. The data needs to be validated. Particularly one cell with
date input. When entering directly into cell the validation rules work and an
error message is generated for invalid data. But when entered through "Input
prompts" the invalid data is accepted. Any way around this?? Please help.