CET vs MST — cities and working rhythm
Most of continental Europe — DACH, Benelux, France, Iberia, Nordics (except Finland), Poland, Czech Republic. Business hours 9 AM – 5:30 PM CET, with a longer lunch (12:30 – 2 PM) in southern countries. Winter: CET (UTC+1); summer: CEST (UTC+2). Big lag against North America — early morning CET overlaps late night ET.
US Mountain — Denver, Salt Lake City, most of Arizona (Arizona notably observes no DST, so it's MST year-round while its neighbours flip). Business hours 9 AM – 5 PM MT.
Time gap: MST is 8.0 hours behind CET (standard-time offsets — daylight-saving flips shift this by an hour twice a year in most northern-hemisphere zones).