> To be slightly more precise, sometimes you want the absolutely correct time
> of day, and somtimes you want an accurately measured interval. This
> distinction is key to good OS timekeeping, because you need to whack around
> the ToD to correct for drift in your local system clock, but interval
> timers must be inviolate (it would be evil to set a timer that never goes
> off because the clock it ticks from got stepped beyond the firing time).

This reminds me the proposal from Dennis Ferguson which addresses this
issue.

ftp://ftp.netbsd.org/pub/NetBSD/mailing-lists/tech-kern/tech-kern.0080
	Message-Id: <199609300210.TAA21368@skank.jnx.com>
	To: tech-kern@NetBSD.ORG
	Subject: settimeofday() versus interval tim{ers,ing}
	Date: Sun, 29 Sep 1996 19:10:35 -0700
	From: Dennis Ferguson <dennis@jnx.com>

	Message-Id: <199609300447.VAA26212@skank.jnx.com>
	Date: Sun, 29 Sep 1996 21:47:55 -0700
	From: Dennis Ferguson <dennis@jnx.com>


ftp://ftp.netbsd.org/pub/NetBSD/mailing-lists/tech-kern/tech-kern.0080
	Message-Id: <199610010551.WAA12607@skank.jnx.com>
	Date: Mon, 30 Sep 1996 22:51:52 -0700
	From: Dennis Ferguson <dennis@jnx.com>

I thought this was fairly reasonable way to resolve the problem.
What's happen about this ?
--
soda