Daylight Savings Time 2012: When do we Fall Back? Purpose
Daylight Savings Time Ends in US/Canada on November 4, 2012
If you live in the USA or Canada, Daylight Savings Time 2011 ends on November 4, 2012. This means that, at 2am, we "fall back" and gain an extra hour of sleep (or nightlife). Arizona, Hawaii, American Samoa, Guam, Puerto Rico, and the Virgin Islands; as well as most of Saskatchewan and some parts of BC, Nunavut and Quebec, do not observe Daylight Savings Time.
UK residents, be aware that the United Kingdom ends daylight savings time on October 30, and so does Ireland.
New Zealand begins Daylight Savings Time on September 25. Most of Australia begins DST on the first Sunday in October and ends at 2am (which is 3am Daylight Saving Time) on the first Sunday in April. Queensland, Northern Territory, Western Australia, and Christmas Island don't observe DST.
iPhone Users, Beware of Daylight Savings Time
If you use your smartphone as your alarm clock, we suggest switching the phone to manual time settings and adjusting the time yourself if you actually have to be somewhere on November 4. The iPhone has failed with DST more than once.
Of course, with the new Apple iOS 6 available, it should be fixed. Then again, considering their problems with Apple Maps, who knows?
Why is Daylight Savings Time Observed?
Adding daylight to evenings benefits retailing, sports, and other activities that exploit sunlight after working hours, but can cause problems for evening entertainment and other occupations tied to the sun. Although an early goal of DST was to reduce evening usage of incandescent lighting, formerly a primary use of electricity, modern heating and cooling usage patterns differ greatly, and research about how DST currently affects energy use is limited or contradictory.
DST clock shifts present other challenges. They complicate timekeeping, and can disrupt meetings, travel, billing, record keeping, medical devices, heavy equipment, and sleep patterns.Software can often adjust computer clocks automatically, but this can be limited and error-prone, particularly when DST protocols are changed.
As modern societies operate on the basis of "standard time" rather than solar time, most people's schedules are not governed by the movements of the earth in relation to the sun. For example, work, school and transport schedules will generally begin at exactly the same time at all times of the year regardless of the position of the sun. However, in non-equatorial regions the total number of hours of sunlight in a day will vary a great deal between autumn/winter and spring/summer. As a result, if "standard time" is applied year round, a significant portion of the longer sunlight hours will fall in the early morning while there may still be a significant period of darkness in the evening.