| The Date and Time are parent of the Date time element. Both are Single and therefore the Value instance field is shared thru inheritance in the Date time type.
To do that, left most bits of the Value sbyte are reserved for the date and the right most for the time.
It is stated that the Date range must be at least ± 20 000 years. To do that 23 bits are required plus 1 sign bit: Giving 24 bits for the date.
It remains 40 bits for the time part in a Date time. Notice that for Date time the time part range is just 0:00 to 24:00. So there is no need for sign bit. With these 40 bits a time resolution of 0.1µs can be reached on a 1 day basis. This is stated as pretty good.
For Time outside of a Date time, the full 64 bits are available, but one is needed for the sign. This allows to support duration of several thousand of years. |