31. The sundial's indicated solar time thus varies from clock time by small amounts that change throughout the year. 32. Greenwich Mean Time is the mean solar time at Greenwich, through which the meridian of zero longitude passes. 33. :: The " equation of time " represents the difference between local mean time and local solar time . 34. The east west component shows the equation of time, or the difference between solar time and local mean time. 35. Standardization has disconnected our clocks and our lives from strict local solar time as a sundial might measure it. 36. Of course, the equation of time can still be used, when required, to obtain apparent solar time from clock time. 37. Solar timing is based on insolation in which the solstices and equinoxes are seen as the midpoints of the seasons.38. Mean solar time has days of equal length, and the difference between the two sums to zero after a year. 39. In this way, decisions made by the original designers of ephemeris time influenced the length of today's mean solar time . 40. Two types of solar time are apparent solar time ( sundial time ) and mean solar time ( clock time ).
