Effects of time zones on North American broadcasting

The scheduling of television programming in North America (namely the United States, Canada, and Mexico) must cope with different time zones. The United States (excluding territories) has six time zones (Hawaii-Aleutian, Alaska, Pacific, Mountain, Central and Eastern), with further variation in the observance of daylight saving time. Canada also has six time zones (Pacific, Mountain, Central, Eastern, Atlantic and Newfoundland). Mexico has four time zones (Pacific, Mountain, Central, and Eastern). This requires broadcast and pay television networks in each country to shift programs in time to show them in different regions.

Canadian broadcasting networks, with six time zones and a much larger percentage of its audience residing in the Mountain Time Zone than in the Central Time Zone, are sometimes able to avoid the issues that affect American programming by airing pre-recorded programs on local time. CBC Television and CTV created delay centres in Calgary in the early 1960s in order to allow programming to air in each time zone based on the region. The province of Newfoundland and Labrador poses a problem which cannot be addressed by delaying content, as most of the province uses a Newfoundland Time Zone one half-hour ahead of the nearby Maritimes region. Saskatchewan also poses scheduling issues as most of the province does not observe daylight saving time, remaining on Central Standard Time year-round.

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