Loop thru sheets with particular name format

This slightly different approach will test if almost any date format has been used and properly identify them all, even if they differ:

12-12-2012
1-1-11
May 2012

Sub NameTest()
Dim ws As Worksheet

For Each ws In Worksheets
    If IsDate(CStr(ws.Name)) Then MsgBox ws.Name
Next ws

End Sub