(State of Michigan)

My doctor wrote me prescriptions for a Schedule II drug. The doctor wrote three separate RX's on the same date. On the second RX he wrote, "fill in 30 days" on the third RX he wrote, "Fill in 60 days".

What is the rules regarding filling the second and third RX? Does 30/60 days mean exactly, or is there a window of days it can be filled. Basically my problem is I am going on vacation, and the 60 days will come and pass while I am gone. From what I can tell the RX expires at day 60, but what about filling early, what is the timing allowed on this?