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Sky Tonight—April 14, Sundial noon and clock noon agree in middle April
Posted By Editor On April 13, 2011 @ 9:04 pm In Earth & Sky | Comments Disabled
Courtesy of EarthSky
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 Every year around mid-April, time by the sun and time by the clock agree. For instance, when the midday sun climbs highest in the sky in mid-April, the sundial reads 12 o’clock noon and your local clock time says 12 o’clock noon.
Your local clock time is the same as standard clock time, as long as you live on the meridian that governs your time zone. If you live east of the time zone line, then your local time runs ahead of standard time. If you live west of the time zone line, local time lags behind standard time.
For simplicity, let’s refer to places that sit right on the time zone meridian, like Denver or Philadelphia. Midday – noon by the sun – reads 12 o’clock noon standard clock time or 1 p.m. Daylight Saving Time.
At present, the length of the day as measured by successive returns of the midday sun is slightly less than 24 hours long. This slight daily discrepancy between the clock and the sun will accumulate until mid-May. In mid-May, midday – noon by the sundial – will come at 11:56 a.m. local clock time or 12:56 p.m. Daylight Saving Time.
After mid-May, day length as measured by successive middays (sundial noons) will become slightly more than 24 hours long. By around mid-June, noon by the sun and noon by the clock will agree once again.
Above photo from Carmichael ‘s photostream.
By Bruce McClure 
EarthSky: Space 
CHANDRA Photo Album 
Universe Today 
StarDate Online 
Sky and Telescope 
National Geographic 
Space Com 
Simostronomy Blog 
Amazing Space 
Scope City 
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URLs in this post:
 www.EarthSky.org: http://www.EarthSky.org
 Image: http://www.berthoudrecorder.com/wp-content/uploads/2011/04/phases-r-09.jpg
 Image: http://www.berthoudrecorder.com/wp-content/uploads/2011/04/apr14.jpg
 How do I translate Universal Time into my time?: http://earthsky.org/astronomy-essentials/universal-time
 It’s summer. What’s noon to you?: http://earthsky.org/earth/its-summer-whats-noon-to-you
 Looking for an astronomical almanac? EarthSky recommends . . .: http://earthsky.org/tonightpost/astronomy-essentials/sunrisesunset-moonrisemoonset-almanacs
 Carmichael: http://www.flickr.com/photos/jlcarmichael/3548676221/
 Bruce McClure: http://earthsky.org/team/brucemcclure
 Astronomy Picture of the Day from NASA/JPL: http://antwrp.gsfc.nasa.gov/apod/
 EarthSky: Space: http://earthsky.org/space
 CHANDRA Photo Album: http://chandra.harvard.edu/photo/
 U.S. Naval Observator Astronomical Information cente: http://www.usno.navy.mil/USNO/astronomical-applications/astronomical-information-center/astronomical-information-center
 Universe Today: http://www.universetoday.com/
 StarDate Online: http://stardate.org/
 Sky and Telescope: http://www.skyandtelescope.com/observing/ataglance/
 National Geographic: http://news.nationalgeographic.com/news/
 Space Com: http://www.space.com/nightsky/
 Simostronomy Blog: http://simostronomy.blogspot.com/
 Amazing Space: http://amazing-space.stsci.edu/tonights_sky/
 The York County Astronomical Society: http://www.ycas.org/tonights_sky.htm
 Scope City: http://www.scopecity.net/
 James S McDonnell Planetarium: http://www.slsc.org/WhatToDo/Planetarium/NightSkyUpdate.aspx
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