World Clock - True Local Time

The true local time is the mean solar time of a certain location, independent from its time zone. It is determined by the location's longitude (east-west direction). For each degree, the time changes for 4 minutes (E+, W-, 360° in 24 h). This calculator enables to choose from big European cities or the input of any longitude in decimal degrees. The 0 degrees line runs through Greenwich, London (England). All locations east of this have a positive degree number, all west of this a negative. The longitude of a certain location can be found out by right clicking in Google Maps on the location and choosing "What's here". The second number of the result is the longitude (the first is the latitude). You can convert other specifications than decimal degrees at the Geo Coordinates Converter. A time different from the current can be entered at "Individual time". For comparing two locations, the calculator has two location lines.

In Central Europe, one degree of longitude on Earth corresponds to about 60 to 80 kilometers to the east or west, the further south, the more. This means that for every kilometer you move east or west, the true local time changes by about one second or a little less. If you go one kilometer east, it is one second later there and the same distance west is one second earlier. This is of course not counting the time it takes to cover this distance.
If you go exactly north or south, the true local time does not change. In general, however, if you go aslant to the cardinal directions, the true local time changes by about one second per kilometer multiplied by the sine of the direction angle.