(1) Unless otherwise specifically provided in these rules, time will be computed by excluding the first day and including the last day unless the last day falls upon a legal holiday, Saturday, or Sunday, in which case the last day also is excluded. When the period of time prescribed or allowed is less than 11 days, intermediate Saturdays, Sundays, and holidays shall be excluded in the computation. For the purposes of these rules, the term "days" means calendar days, unless otherwise specified.
(2) Mailed documents are presumed to be mailed on the day they are dated. That presumption may be rebutted by a showing of the postmark. The burden of proof for showing that a document was mailed on a date different than the document's date rests with the person who claims that it was mailed on the different date. A party which alleges that it did not receive notice by mail of a board proceeding has the burden of proof in showing that the party ought to be granted relief. The party must present clear and convincing evidence to rebut the statutory presumption contained in 26-1-206, MCA, that a letter duly directed and mailed was received in the regular course of the mail.
(3) All questions regarding alleged nonreceipt of mail, or whether an appeal was timely made must be resolved by the board.
(4) If a rule requires a response within a certain number of days after the board mails a document, the party responding is not afforded any additional time for mailing in responding to the board. The response must be received by the board within the time allotted by rule. As provided for in ARM 24.26.203, both facsimile and electronic mail filing is accepted.