anomalistic year

(ənŏm'əlĭs`tĭk), time required for the earth to go from the perihelion point once around the sun and back to the perihelion point. It is 365 days, 6 hr, 13 min, 53.0 sec of mean solar time (see solar timesolar time,
time defined by the position of the sun. The solar day is the time it takes for the sun to return to the same meridian in the sky. Local solar time is measured by a sundial.
..... Click the link for more information. ). The anomalistic year is longer than the sidereal yearsidereal year,
time required for the earth to complete an orbit of the sun relative to the stars. The sidereal year is 365 days, 6 hr, 9 min, 9.5 sec of mean solar time (see solar time).
..... Click the link for more information. and the tropical yeartropical year,
time between successive vernal equinoxes; 365 days, 5 hr, 48 min, 46 sec of mean solar time (see solar time). The tropical year is the basis of the year used in the Gregorian calendar.
..... Click the link for more information. because of the eastward motion of the line of apsides (see apsisapsis
(pl. apsides), point in the orbit of a body where the body is neither approaching nor receding from another body about which it revolves. Any elliptical orbit has two apsides.
..... Click the link for more information. ), which is caused by the slow rotation of the earth's orbit as a whole.

anomalistic year

The time interval of 365.259 64 days between two successive passages of the Earth through the perihelion of its orbit. The anomalistic year is longer than the sidereal and tropical years because of the advance of the perihelion caused (mainly) by planetary perturbations.