[Note: Some have noted that it should be Daylight Saving Time, without the pluralization of Saving. I, like many, use it more as a general-use title rather than a literal statement - given that it isn't actually saving daylight - and I generally hear it referred to as Daylight Savings Time. Just thought I should mention that.

If one wants to be a pedant, I believe it should actually be Daylight-Saving Time]

The Ontario government caved today, rashly deciding to follow the lead of a ludicrous U.S. energy bill rider, extending Daylight-Saving Time by three weeks in the spring, and a week in the fall (switching into DST on the second Sunday of March, rather than the first Sunday of April as it currently is, and switching back to Standard time on the first Sunday of November rather than the last Sunday in October).

Given that many don't entirely understand DST, I thought I'd share a graph I made some time back (I originally planned on turning the source algorithm into a web service to allow one to punch in the inputs such as location and generate their own graph, but could never justify spending the time on it).

All values are calculated for Toronto, Ontario, for 2005. The red line represents EST sunrise, the yellow EST solar noon, while the cyan line represents EST sunset. The purple lines represent the 9-5 workday, adjusted in the summer months to account for DST (where 9-5 is really 8-4). The blue lines represent the extensions brought about by this change (3-weeks earlier in the spring, one week later in the fall). To recap - only the workday period on the graph above calculates in DST (e.g. the 8pm sunset during the summer is 9pm on the clock during DST, and the 4:20am sunrise is actually 5:20am on the clock).

As much as I dislike the incredibly costly confusion and complexity of DST (my two and a half year old still hasn't adjusted), there is a small amount of logic behind it - Presuming that human beings don't naturally adapt to the sun coming up earlier during the summer, DST moves an hour of this presumably unused time into the traditional post-work hours, "lengthening" the evening (not really lengthening the evening, but artificially doing so by moving the traditional 1950s work hours earlier in the day).

Many people would argue against this, saying that the summer hours give them an opportunity to jog, garden, go to the gym, and otherwise take advantage of the extended pre-work hours. Nonetheless, DST is geared towards those who do nothing until their pre-work preparation (e.g. the alarm clock goes off an hour and 30 minutes before the work day starts). For those people DST is entirely beneficial.

Extrapolate that logic out, though, and there should be a second layer of DST that moves the clock yet another hour forward during May to September. Maybe an hour more during June. Perhaps we should have a dynamic clock, such that 9am is an hour after sunrise year round.

Humor aside, there is a tremendous risk of this DST extension, especially coming into force so quickly. Having worked with a number of daylight-saving time related software problems (please use UTC people, or at the very least disregard DST), I would wager that there will be significant ramifications of this. Millions of dollars will need to be spent preparing for, and then cleaning up after, what many seem to think is a simple date change.

Anyone interested in the source data that I generated for this can find it here (it's a Microsoft Excel worksheet).

http://www.yafla.com/