4 ms·
Of course doesn't account for Daylight Savings, or the inherent inaccuracies of time zones?
by th0ma5 12y ago
Of course doesn't account for Daylight Savings, or the inherent inaccuracies of time zones?
- sp332 12y agoYou can adjust it forward or back however far you want by turning it.
- mseebach 12y agoA sun dial will only ever show you solar time, not whatever political abstraction passes for "time" wherever you happen to be. Fun fact: Only with the advent of railroads did time begin to be synchronized in larger areas. Until then, each city and town set it's own time, based on the local solar time. https://en.wikipedia.org/wiki/Railway_time https://en.wikipedia.org/wiki/Railway_time There exists public clocks that track both local and standard time: https://en.wikipedia.org/wiki/The_Exchange,_Bristol#Clock https://en.wikipedia.org/wiki/The_Exchange,_Bristol#Clock
- Houshalter 12y agoYou'd need to adjust it like you would a normal clock. But in theory you could make one that could do it automatically; the angle the sun is at also tells you what time of year it is.
- mnw21cam 12y agoNot uniquely. The angle of the sun (its height above the horizon at midday) tells you that you must be at one of two times of the year. Those two times have different solar time corrections.
- Houshalter 12y agoPerhaps http://solarwiki.ucdavis.edu/@api/deki/files/106/solar_position.jpg http://solarwiki.ucdavis.edu/@api/deki/files/106/solar_posit... The time corrections are based on the length of the day which is based on the angle of the sun. So it won't be perfect but it might correlate fairly well.
- mnw21cam 12y agoUnfortunately not. http://upload.wikimedia.org/wikipedia/commons/1/12/EquationofTimeandAnalemma.gif http://upload.wikimedia.org/wikipedia/commons/1/12/Equationo... If you look at the bottom right part of the image, you will see that time difference cannot be uniquely determined from declination. Declination will narrow down the time difference to two times of year, which have very different time differences, but you will need some other information to determine which of the two times of year it actually is. For example, when the declination is neutral, at the equinox, it may be the spring or autumn equinox. Those two times of the year have different time differences - one is plus seven minutes while the other is minus seven minutes.