6:00 am PDT might be unsuitable for MT time zone
When planning a call between Pacific Daylight Time and Mountain Time, you need to consider time difference between these time zones. PDT is 1 hour behind of MT.
It is 6:00 am in PDT. This does not fall within the span of usual working time between 10:00 am and 6:00 pm in MT, but it still might be suitable to arrange a meeting, since it would be 7:00 am in MT, which is between 7:00 am and 11:00 pm MT time.