Michigan Administrative Code — Department of Treasury (tax rules)
Mich. Admin. Code R 388.17 — Business and calendar days
Rule 17. (1) Unless otherwise required by these rules, when the act, these rules, or
any other guidance published by the department including, but not limited to, global
instructions, policies, procedures, or guidelines refer to time periods of 7 days or less, it
shall mean business days. Time periods greater than 7 days, shall mean calendar days.
(2) Pursuant to MCL 211.24f(2)(b), “year” means the 12 succeeding months starting
upon and including the first anticipated levy.
Source: official text