why the length of days begin from the second half of days in winter?

Question

when days begin to long from the bigining of winter first it begin fro afternoon but not from morning and afternoon equall why?

Answer 1

Two things are going on, the travel of the earth around the sun and the angle of the earth's axis to the axis of the rotation of the planets around the sun (the ecliptic). If you were to plot the times of the center of the day (half way between sunrise and sunset) you would find it is shifting later and later in the day from the time of equal length days and nights in the fall (about Sept.21). This shift overwhelms the lengthing of the day, so sunrises continue to occur later for a while and the sunsets get later and later at a larger rate. Eventually, the sunrises start getting earlier and we get to an equal length day/night (equinox) in the spring. It has to do with the regular rotation of the earth while traveling in an ellipical orbit.

Answer 2

Its due the wobble in the earth's rotation about its axis. Too complicated to explain here. Study your text!