Creating a new sheet with date in the sheet name

[hermoraunio]

Sub NewCalendar()
' Make new calendar

On Error GoTo ProcError

    Dim ShtName$
    
    Sheets(2).Copy After:=Sheets(1)

    ShtName = Range("H1").Value + 1
    
    Sheets(2).Name = ShtName
    
    Range("H1").Value = ShtName
    
    
ProcError:
    
    Exit Sub
    
    
End Sub

This works just fine when I create first copy, but after that it's type mismatch (error 13)

EDIT: As this is my first post here, I forgot to explain what I want to do here.
I want to create a new sheet with a name "24.7.2013" if the previous date was "23.7.2013" and so on.
Every H11 Cell in every sheet contains a date. I am setting the variable ShtName a value (the date from newest sheet cell H11 + 1).
Then I copy the newest sheet and rename it with ShtName. Sorry if this seems messy. It's actually quite simple, I'm just not so good at explaining stuff.