CAST DateTime Value To A Fixed-point Number

I'm reviewing the CAST function using Microsoft SQL server. I generally understand the functionality, but my confusion lies in the results of a particular script which casts a DateTime value to a fixed-point number.

It is as follows:

DECLARE @From DATETIME
DECLARE @To NUMERIC(10,5)

SET @From = '2009-10-11T11:00:00'
SET @To = cast(@From AS NUMERIC(10,5))

PRINT @To

This results in: 40095.45833

I am completely lost as to how 40095.45833 = 2009-10-11T11:00:00. I just do not understand the how that fixed point number equates to that source DateTime data.