3x280+380+450+(365x2)=2400
The Earth rotates on its axis once each day. It is, in fact, the rotation of the Earth that creates a "day".However, due to the revolution of the planet around the Sun the a day can be taken to mean in reference to the sun or in reference to stars. The difference is accounted for by noticing the difference between a sidereal day and a solar day. A sidereal day is the time it takes for the Earth to spin once in reference to the vernal equinox rather than in reference to the sun. Over the course of a year the difference between the sidereal days and solar days adds up to a day as the revolution of the Earth around the sun masks one entire rotation of the axis.