Passing sixth grade should require demonstrating a way to find the local noon on a day when there is at least 6 hours of sun and 6 hours of dark using only basic tools. If the demonstration is off because of magnetic north vs true north, the student is required to tell the examiner that fact, but no correction is required. The 6 hours sun/dark is for those who live in areas where there is less since midnight sun makes this weird.
I'll settled for no DST, but I have to work with people all over the world and it is a pain to discuss times.