Timezones CGC1P

Time Zones The Earth has 24 times zones because it takes the Earth 24 hours to revolve around the sun Each time zone is one hour apart Each time zone is 15 longitude 360 / 24 = 15 Every place within a time zone has the same time, referred to as its standard time

History of Timezones Standard time zones were not required prior to the 1800s because it was impossible for people to travel large distances in a short period of time The development of rapid railway transportation changed travel dramatically, allowing people to travel large distances quickly

History of Timezones This caused confusion, since every town set their own clocks by the sun Ex: 8:00 in Ottawa would be about 7:45 in Toronto A Canadian engineer same Sir Sandford Flemming proposed a system of standard time zones

Canada’s Timezones Canada spans 6 time zones We are in the Eastern Standard Time Zone If it is 1:00pm in Ottawa it is the same in all of this time zone In Canada this includes all of Quebec and most of Ontario (as far west as Thunder Bay) In the US this includes all of the eastern states, as far west as Michigan

Global Time Zones The prime meridian is the centre time zone The zone extends 7.5 on either side of the 0 longitude Time in this zone is called universal time (UT) and the standard time in other zones is compared to it Time zones west of the prime meridian are earlier than the universal time (the time at the prime meridian) E.g. if UT is 12:00am, next time zone west is 11:00pm.

Global Time Zones Time zones east of the prime meridian are later than the universal time (the time at the prime meridian) E.g. if UT is 12:00am, next time zone east is 1:00am.

Global Time Zones Some countries modify time zones (change them from straight lines) for political reasons (for example, it’s more convenient) For example all of China is in same time zone, so all of the country is on the same time. Some places are located where time zones meet For example St. John's, so it is given half a time zone (1/2 an hour)

Daylight Savings Time Many parts of the world change their time according to the season During the summer, daylight saving time is used to extend daylight hours For example the sun in standard time would set at 8:00pm but when time is in daylight savings it would set at 9:00pm (therefore 1 more hour of daylight)

Daylight Savings Time Energy is saved and people get to enjoy more of the day i.e. wake up when light, go to bed when dark In Canada time is changed to daylight saving on the second Sunday in March and ends the first Sunday of November

Set the clocks ahead or back? “Spring ahead, fall back” This year, daylight savings time began on March 13 We set the clocks ahead one hour It will end on November 6 We will set the clocks back one hour So when your alarm goes off at 7am, it will feel like 8am - like getting to sleep in an extra hour!

Observe Daylight Savings Time Tried it but gave it up Never used it

What’s up with Saskatchewan? Saskatchewan is naturally located within the Mountain Standard Time (MST) – the same timezone as Alberta. Under The Time Act of 1966, Saskatchewan adopted Central Standard Time, so shares the same timezone as Manitoba But since they don’t observe Daylight Savings time, they share the same time as Alberta during the summer months and the same time as Manitoba during the winter months