12:00 pm MST / 3:00 pm ET is a convenient time to arrange a meeting
When planning a call between Mountain Standard Time and Eastern Time, you need to consider time difference between these time zones. MST is 3 hours behind of ET.
It is currently 12:00 pm in MST, which is a suitable time to arrange a call or meeting. In ET, the time would be 3:00 pm - a usual working time of between 12:00 pm and 6:00 pm.
If you want to reach out to someone in ET and you are available anytime, you can also schedule a call between 4:00 am and 8:00 pm your time. This time span will be between 7:00 am and 11:00 pm ET time.