Need macro to run on mulitple sheets

Have working macro that does what I need (hiding columns based on criteria):

Sub Day21Window()
'
' Day21Window Macro
' Create View Window After Date Set
'


Application.ScreenUpdating = False

For Each Col In Range("H1:IG1").Columns
    If Col.Columns.Cells(68, 1) = "H" Then
        Col.EntireColumn.Hidden = True
    Else
        Col.EntireColumn.Hidden = False
    End If
Next Col
          
            Application.ScreenUpdating = True

   
End Sub

It currently executes in Sheet A, but I need it to also execute in Sheets B, C, and D (potentially more) without copying and executing in each sheet individually. Do I "nest" this macro in another macro, or does it become it's own set of instructions?? Thank you.