Local mean time

<h2 id="past-use">Past use</h2>
<p>Local mean time was used from the early 19th century, when local <a href="/facts/Solar_time/aYq9JqwI">solar time</a> or <a href="/facts/Sundial/RWM823m2">sundial</a> time was last used until <a href="/facts/Standard_time/3dKMYnjM">standard time</a> was adopted on various dates in the several countries.   Each town or city kept its own <a href="/facts/Meridian_(geography)/zdbk1YPt">meridian</a>, so locations one degree of longitude apart had times four minutes apart.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> This became a problem in the mid 19th century when railways needed clocks for <a href="/facts/Railway_time/wstDWUbH">railway time</a> that were synchronized between stations, while local people needed to match their clock (or the church clock) to the time tables. <a href="/facts/Standard_time/3dKMYnjM">Standard time</a> means that the same <a href="/facts/Time/HceJKUGB">time</a> is used throughout some regional time zone—usually, it is at an offset from <a href="/facts/Greenwich_Mean_Time/JpSIdWsn">Greenwich Mean Time</a> or the local mean time of the <a href="/facts/Capital_city/p06rGdJC">capital</a> of the region.
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<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Day/MTAtWLDj">Day</a></li>
<li><a href="/facts/Time_zone/x5JzdlX8">Time zone</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Urban, Sean E.; Seidelmann, P. Kenneth (2013). Explanatory Supplement to the Astronomical Almanac (3rd ed.). Mill Valley, CA: University Science Books. pp. 13, 231, 239. <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Finch, Vernor C.; Glenn T. Trewartha; M. H. Shearer; Frederick L. Caudle (1943). Elementary Meteorology. McGraw-Hill Book Company, Inc. p. 17. ASIN B005F644PG. <a href="/wiki/ASIN_(identifier)" target="_blank">/wiki/ASIN_(identifier)</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
</ol>

Local mean time open-in-new

Local mean time