Rule 409. In computing any period of time prescribed or allowed by these rules, by order of the commission or the presiding officer, or by any applicable statute, the day of the act, event, or default after which the designated period of time begins to run is not included. The last day of the period is included, unless it is a day on which the commission's offices are not open for business, in which case the period shall run until the end of the next day on which the commission's offices are open for business.
Mich. Admin. Code R. 792.10409