Regional context
Timezones across North America
North America runs five continental-US timezones (Eastern, Central, Mountain, Pacific, Alaskan) plus Newfoundland (a 30-minute offset from Atlantic Time — one of the few 30-minute timezones outside Asia). DST is nearly universal (except Arizona, Hawaii, most of Saskatchewan) and runs March → November. Business scheduling defaults to Eastern for multi-office US corporations regardless of headquarters.