Datetime functions.
Copyright (C) 1999, Massimo Dal Zotto <dz@cs.unitn.it>

This software is distributed under the GNU General Public License
either version 2, or (at your option) any later version.


I have written some new funtions for time and date data types which can
be used to extract hour,minutes,seconds from time values, and year,
month,day from a date. There is also a time_difference and functions
to convert a time to minutes or seconds.

There are also new input/output functions for the time data type which
allow the insertion of time attributes with value 24:00:00.
This can be useful if your application needs to compute time difference
from two time values representing an elapsed time of 24 hours.

Massimo Dal Zotto <dz@cs.unitn.it>
