Does Anyone understand this code?

[kepbem]

I am new to this forum, i have created this database, however the timetables will not reset themselves. They have done previously, can anyone help?

Option Compare Database
Option Explicit
 
'------------------------------------------------------------
' Macro1
'
'------------------------------------------------------------
Function Macro1()
On Error GoTo Macro1_Err
Dim db As DAO.Database, rstdatechange As Recordset
 
Set db = CurrentDb()
Set rstdatechange = db.OpenRecordset("datechange")
 
On Error GoTo Macro1_Err
 
        If (rstdatechange![last updated] < Date) Or ((rstdatechange![last updated] = Date) And (Time >= rstdatechange![last time])) Then
        DoCmd.RunMacro "Create History", , ""
        DoCmd.RunMacro "Delete Timetables", ""
        DoCmd.RunMacro "Recreate Timetables", , ""
        DoCmd.OpenQuery "change update date", acNormal, acEdit
        DoCmd.Close acQuery, "change update date"
        End If
 
 
 
Macro1_Exit:
    Exit Function
 
Macro1_Err:
    MsgBox Error
    Resume Macro1_Exit
 
End Function