L.2.16.9.3 Combined Date and Time Conversion for Serial Values

Any date component can be added to any time component to produce a serial value for that date/time combination. The resulting serial value encodes that date whose (positive or negative) time span from base date in the respective date-base equals the serial value.

For the 1900 date base system:

The serial value -2337.999989… represents 1893-08-05T00:00:01Z The serial value 3687.4207639… represents 1910-02-03T10:05:54Z The serial value 1.5000000… represents 1900-01-01T12:00:00Z The serial value 2958465.9999884… represents 9999-12-31T23:59:59Z

For the 1904 backward compatibility date base system:

The serial value -3799.999989… represents 1893-08-05T00:00:01Z The serial value 2225.4207639… represents 1910-02-03T10:05:54Z The serial value 0.5000000… represents 1904-01-01T12:00:00Z The serial value 2957003.9999884… represents 9999-12-31T23:59:59Z