Questione giuridica chiave
Whether the appeal to the cantonal supervisory authority was proven to have been filed within the statutory deadline.
Decisione estratta
The appellants did not prove that the appeal was deposited on 30 November 2009; the later postal stamp controlled and the appeal was untimely.
Motivazione estratta
The decisive date is the deposit with the postal office, normally shown by the postal stamp. The appellants failed to demonstrate arbitrariness in the cantonal findings based on postal information about collection times.