(your actual solar time)

Step 1: First look up your longitude. Examples: Paris F: 48n52, 2e20, France New York (US): 40n43, 74w0, US Amsterdam NETH: 52n22, 4e54, Netherlands Den Hague NETH: 52n05, 4e19, Netherlands Tokyo, JAPAN: 35n42, 139e46, Japan For New York e.g. must below next be entered at longitude degree 74 and with the minutes 0 ! New York (US) is west (w) of Greenwich Longitude degree: Longitude minutes: Position to Greenwich: eastwest   Step 2: Next enter below the data of the here presented GMT*-time. (N.B.: You can thus also calculate your suntime for a GMT-time different from the present one)  Hours GMT Minutes GMT Year Month Day Having a clock thus set to the sun requires, if you want to keep it within a margin of a couple of minutes, that you correct the time so about once a week, Not doing this can the difference quickly amount to half an hour (from Nov. 5 to Febr. 5 e.g.). Correcting for the sake of nature can best be done with natural regularity: on Cakra-sundays e.g., see below: To check this by hand you need to consult the pages about the equation of time and the FCO-calendar

 
*: GMT: Greenwich Mean Time - the time standard for the entire world.
It is mean local time to the longitude of zero irrespective summertime. 
It is also called UTC (Universal Time Coordinated) or worldtime.
The time on your clock differs from this one
depending your time zone and summertime.