The latitude is the angular distance of a point of the Earth's surface, North or South of the Equator as measured from the _____.

Consider the following statements:

$1$. The vernal equinox falls around $21\mathrm{st}$ March.

$2$. On equinox, the Sun is directly overhead at the equator.

$3$. The changes in the day length on equinox result from the changes in the tilt of the Earth with respect to the Sun.

Which of the statement(s) given above is/are correct?

Consider the following statements:

$1$. International Date Line is drawn zigzag to avoid landmass.

$2$. International Date Line is $180° \mathrm{W}$ as well as $180° \mathrm{E}$ of Greenwich.

$3$. A ship sailing westward from Greenwich when crossing International Date Line would put forth the date by a day.

Which of the statement(s) given above is/are correct?