Well, isn't that just a happy little math problem! 365 times 2 is 730. Just imagine all the possibilities that number holds, like painting 730 beautiful little trees or clouds in the sky. Remember, there are no mistakes in math, just happy little accidents waiting to be solved.
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.