skfjeofh

As has been noted in another comment, the article makes that statement, but skips over the implications of the constant apparent motion of the sun for the length of day.

It gives the impression that, geometrically speaking, there is a day on (or near) the equinox which has equal darkness and daylight. Of course, this isn't guaranteed at all, and certainly not for every point on the earth's surface.

The article is missing the most disappointing fact of all, though.

If there was a whole 24-hour period during which the sun was on the celestial equator, then 12 hours would be day and 12 night (going by the time the centre of the sun's disc rose and set).

But the sun is always moving along the ecliptic, so the day we call the equinox is just the 24hr period within which the sun crosses the equator, which is an instantaneous event.