Date: Sun, 18 Dec 2016 12:38:37 -0700 From: Brian Inglis <Brian.Inglis@SystematicSw.ab.ca> Message-ID: <0113fd16-8392-7446-be54-e13f6ecf96ea@SystematicSw.ab.ca> | Probably less positive impact of DST on those in sub-tropical | southern latitudes That's assuming you're referring to the northern hemisphere of course. But yes, in tropical areas summer time makes essentially no sense, as there's almost no variation in the day length year round - what's more, in mid tropical areas, summer typically is not near the actual equinox - in Thailand for example, mid summer happens in mid April - just after the equinox - which is just after the sun passes overhead (goes from being south to being north). There would (should) presumably be another summer at the start of September, but that's a monsoon season, the clouds reflect the sunlight, and it doesn't get so hot. But just like the rest of the northern hemisphere, winter (if you can call it that - but it is cooler) is January - so there is quite rapid transition from winter to summer, and then a longer intermediate period from summer to winter again. This doesn't mean that the clocks have to be on "natural" time though, Singpapore and Malaysia "should be" UTC+0700 (and were for a long time) but use UTC+0800 so they're running in the same zone as Hong Kong (and closer to Japan) for example. (tzdata has Singapore as 06:55:25 LMT before stadardised time, and Kuala Lumpur on 06:46:46 - yet they're both +0800 now - since 1982 - just as if they have "year round daylight saving") | If I understand correctly what you're saying, I must disagree, as | anyone involved in North American dealing with stocks, currencies, | commodities, energy, works from before 9ET until after 3ET, | regardless of where they are across the country, No, that is exactly what I was saying. The point was that sometimes there are arguments by people opposed to summer time (or sometimes by those in favour) along the lines of "if you don't like what time you have to work, just go earlier/later, don't move the clocks and affect everyone else" - where for most of the population, that simply isn't possible (which is just what you said). External forces control the clock hours at which people must work, and it is very very hard to change that - either for indivisuals, or the employers they work for, however the government can adjust the clock setting wrt the sun, which affects everyone, leaving those who have to deal with international issues to find a way to cope. Note that I am not arguing in favour (nor against) summer time, just against some of the arguments that are sometimes made against (and sometimes for) it. Also, if the head banging that Randal referred to was more because people want to call an adjusted time zone "daylight saving time all year" instead of just calling it "standard time" then that's (the head banging) is just as pointless ... it doesn't matter in the slightest what anyone calls the time, it is just a label, and arguing for one label over another is mostly wasted effort, and certainly isn't worth getting upset about, no matter how stupid you think it. What clock times the sun sets and rises, and whether or not that should be adjusted during the year are things you can argue about, what any of that is called affects nothing (provided that people understand what is meant) and arguing about it isn't worth the effort - this said despite that I sometimes comment on the stupidity of calling anything "daylight saving time"! kre