'так добавляют свойства удобственно именно в процедуре общего модуля без параметров так как можно запускать вручную'
Public Sub add_prop()
CurrentProject.Properties.Add ( "firstdate" ),  0 
CurrentProject.Properties.Add ( "lastdate" ),  0 
End Sub

'так  устанавливаю месячный период'

Public Sub setperiod(data As Date)
Dim prp As Property
CurrentProject.Properties( "firstdate" ) = firstdate(data)
CurrentProject.Properties( "lastdate" ) = lastdate(data)
End Sub

'прочее'

Public Function gcy() 'GET CURRENT YEAR'
gcy = year(CDate(CurrentProject.Properties( "firstdate" )))
End Function

Public Function firstdate(data As Date)
firstdate = CDate( "1  " & CStr(Month(data)) &  "."  & CStr(year(data)))
End Function

Public Function gfd()
'get first date'
gfd = CDate(CurrentProject.Properties( "firstdate" ))
End Function

Public Function gld()
'get last date'
gld = CDate(CurrentProject.Properties( "lastdate" ))
End Function