The board, however, may by resolution entered upon its minutes fix any day of the month for its regular monthly meeting, or if more than one regular meeting is to be held each month it may fix the days for such regular meetings. When more than one regular meeting is held each month, the day of the first such meeting in January is the regular monthly meeting day in January for the purposes of this division. The change shall not be effective until the resolution proposing it has been published once a week for two successive weeks in a newspaper published in the office county.