Kernrechtsfrage
Whether the cantonal appeal was filed within the 30-day deadline and sufficiently proven as timely posted
Extrahierter Entscheid
The appellant did not disprove the cantonal finding of lateness; a handwritten note on the envelope was only a party assertion and not proof of timely posting.
Extrahierte Begründung
Under Art. 8 CC, the burden of proving timely procedural filing lies with the party asserting timeliness. The postal stamp supported tardiness, and the appellant’s allegation of an earlier mailbox deposit was insufficient.