With Sheets ("mySheet")
startDate = Application.Min( .Range("a:a"))
endDate = Application.Max( .Range("a:a"))
End With

Put a period in front of Range and you won't have to select the sheet.
Otherwise, using the With construct does nothing.

I don't know why you are getting a type mistmatch. Place

Option Explicit

at the top of all your modules and see if the routine where the error occurs
can see your variables (startDate and endDate)

I don't know where they are declared, but if at the top of a module you
might declare them as

Public startDate As Date
Public endDate As Date

--
Regards,
Tom Ogilvy

"Patti" wrote in message
...
Can someone pls tell me what I'm doing wrong?

Dim startDate As Date
Dim endDate As Date

startDate = Application.Min(Range("a:a"))
endDate = Application.Max(Range("a:a"))

Later, I try to use this in a different sheet I get type mismatch no
matter
what I try:

Cells("Cl").Value = "Summary for " & startDate & "- " & endDate

I also found that I need to activate the sheet that has the dates because

With Sheets ("mySheet")
startDate = Application.Min(Range("a:a"))
endDate = Application.Max(Range("a:a"))
End With

is still trying set the dates from the active sheet.

Thanks in advance!