For example, some decades ago France switched to using time zone UTC + 1 ( which is local mean time for longitude 15 & deg; E ) in winter and UTC + 2 ( 30 & deg; E ) in summer ( daylight saving time ).
22.
:UTC + 05 : 45 ( which probably does " not " need its own separate article ) explains that the local mean time, which is purely geographically derived ( longitude ), is 5 : 41 : 16 ahead of talk ) 22 : 24, 18 October 2010 ( UTC)
23.
The " width " of the figure is due to the equation of time, and its angular extent is the difference between the greatest positive and negative deviations of local solar time from local mean time when this time-difference is related to angle at the rate of 15?per hour, " i . e . ", 360?in 24 h.
24.
:According to Nigeria's entry in the " africa " file which is part of the timezone data incorporated into most unix-like operating systems ( the most recent version is available from ftp : / / elsie . nci . nih . gov / pub / tzdata2005m . tar . gz ), there have been no changes since September 1919 ( when Lagos switched from local mean time to the present UTC + 01 : 00 time zone ) . & mdash; AlanBarrett 16 : 14, 2 October 2005 ( UTC)
25.
The origin of the analemma, where the solar declination and the equation of time are both zero, rises and sets at 6 a . m . and 6 p . m . local mean time on every day of the year, irrespective of the latitude of the observer . ( This estimation does not take account of atmospheric refraction . ) If the analemma is drawn in a diagram, tilted at the appropriate angle for an observer's latitude ( as described above ), and if a horizontal line is drawn to pass through the position of the Sun on the analemma on any given date ( interpolating between the date markings as necessary ), then at sunrise this line represents the horizon.
