10:00 pm MDT might be unsuitable for PT time zone
When planning a call between Mountain Daylight Time and Pacific Time, you need to consider time difference between these time zones. MDT is 1 hour ahead of PT.
It is 10:00 pm in MDT. This does not fall within the span of usual working time between 9:00 am and 5:00 pm in PT, but it still might be suitable to arrange a meeting, since it would be 9:00 pm in PT, which is between 7:00 am and 11:00 pm PT time.