22 March, 2012

Daylight saving time for India

If you search for "Daylight saving time USA"in Google, it returns:

Daylight Saving Time (United States) began Sunday, 11 March 2012, 2:00, and ends Sunday, 4 November 2012, 2:00.Except Arizona and Hawaii. Move your clocks ahead 1 hour in spring and back 1 hour in fall ("Spring forward, fall back").

This got me thinking:

Q. In India, during summer (i.e. now) how much EXTRA sunlight do we get in the morning? Do we get equal no. of EXTRA hours in the evening? Of course not, so what is the difference? Is it significant?

Q. Secondly, how much % energy is spent on lighting (houses, offices, roads etc.)? Is it significant?


Following are some no. of New Delhi, I intentionally chose a city in North India, where difference will be more.


Date             SunriseSunsetThis dayDifferenceTimeAltitudeDistance

24 Feb 2012    06:52    18:17    11h 25m 03s    + 1m 38s    12:34    51.7°     148.031
25 Feb 2012    06:51    18:18    11h 26m 42s    + 1m 38s    12:34    52.1°     148.064
26 Feb 2012    06:50    18:19    11h 28m 21s    + 1m 39s    12:34    52.5°     148.098
27 Feb 2012    06:49    18:19    11h 30m 01s    + 1m 39s    12:34    52.9°     148.132
28 Feb 2012    06:48    18:20    11h 31m 41s    + 1m 40s    12:34    53.2°     148.167
29 Feb 2012    06:47    18:20    11h 33m 21s    + 1m 40s    12:34    53.6°     148.201

26 Mar 2012    06:18    18:36    12h 17m 52s    + 1m 43s    12:27    63.8°     149.244

27 Mar 2012    06:17    18:36    12h 19m 35s    + 1m 42s    12:26    64.2°     149.286
28 Mar 2012    06:16    18:37    12h 21m 18s    + 1m 42s    12:26    64.6°     149.328
29 Mar 2012    06:15    18:38    12h 23m 01s    + 1m 42s    12:26    65.0°     149.370
30 Mar 2012    06:13    18:38    12h 24m 43s    + 1m 42s    12:26    65.3°     149.412
31 Mar 2012    06:12    18:39    12h 26m 25s    + 1m 42s    12:25    65.7°     149.454

Source: http://www.timeanddate.com/worldclock/astronomy.html?n=176&month=3&year=2012&obj=sun&afl=-11&day=1

Remember North India are some really populous states (as big as some European countries) , so a serious study is needed to conclude is Daylight Saving Time for India will result into energy savings (which is scarce).



Also remember that typical Indian office, work starts after 9:30 AM so we are already NOT using morning sunlight. In summer, it is whopping 3 hours after sun rise. Of course assumption here majority buildings have architecture that uses sunlight.