This is the tropical year or the time from one equinox to its return.
Have you ever quite realized what the tropical year is like?
And now, by a variety of indications, it was manifest that the winter of the tropical year was at hand.
The time occupied by the sun, in passing from the equinoctial point round to the same point again, is called the tropical year.
This would indeed be the case if the mean value of the civil year of the Julian calendar was exactly equal to the tropical year.
By taking this amount from the sidereal we obtain the tropical year, which has reference to the seasons and the calendar.
Consequently, the length of the tropical year is now about ten seconds less than it was in the time of Hipparchus.
Limits of variation of the tropical year modified by the disturbing action of the sun and moon upon the terrestrial spheroid.
Laplace found that the extent to which the tropical year is liable to vary from this cause, amounts to thirty-eight seconds.