RE: Where are we?

From: Jack.Lang@ntl.com
Date: Tue, Oct 12 1999


Message-ID: <D7114154CB8DD2118F030008C70D52FC072D8F@mast-ln0-se01.private.ntl.com>
From: Jack.Lang@ntl.com
To: Harald@Alvestrand.no, djz@corp.webtv.net, www-tv@w3c.org
Cc: dean@corp.webtv.net
Date: Tue, 12 Oct 1999 10:27:15 +0100
Subject: RE: Where are we?


Time is tricky in TV-land, as few stations keep to schedule, and there are
variable delays in the transmission chain, besides DVCR functions. I argue
that time values should be typed, otherwise which type of time do you refer
to:

Absolute time (e.g. GMT or UTC)
Local time ("do something at midnight locally")
Scheduled time (e.g. 10 minutes after Southpark is scheduled to start in the
local EPG)
Actual time transmitted by the originator ("Programs are running 10 mins
late")
Actual time received (may be minutes later)
Actual time viewed (if DVCR functions enabled)
Relative to start of program (e.g. NPT)
and others

Unfortunately some of the more useful information needed (such as schedule
slippage or NPT)doesn't usually make it through the transmission chain at
present. 

Jack Lang

>>>>>>>>>>>>>>>>>>>>>
- On the principle of "all URLs escape the context for which they were
   created", I would VERY much like to ask for the mandatory inclusion of
   timezone. You never know who is going to try to watch this, via what
medium.

So your example (also including a feed identifier) would become

tv:east.pbs.org#1999-10-11T13-00-00+0500/1999-10-11T13-30-00+0500

and be unambiguous whether it was looked up in Texas or California.

                       Harald


--
Harald Tveit Alvestrand, Maxware, Norway
Harald.Alvestrand@maxware.no