PGTYPEStimestamp_sub_interval(timestamp * tin, interval * span, timestamp * tout)
{
	interval	tspan;

	tspan.month = -span->month;
	tspan.time = -span->time;


	return PGTYPEStimestamp_add_interval(tin, &tspan, tout);
}
PGTYPEStimestamp_sub_interval(timestamp * tin, interval * span, timestamp * tout)
{
	interval	tspan;

	tspan.month = -span->month;
	tspan.time = -span->time;


	return PGTYPEStimestamp_add_interval(tin, &tspan, tout);
}