[Xastir] Using time field data in Xastir objects

[Tom Tessier]

Yes, I see how this would cause time confusion. At least what I'm looking at
in volunteers conducting SAR, it's (supposed!) to be a more controlled
situation. If people are participating in a search, some attempt would be
made to ensure each person's timestamp generating device is set within a few
seconds of one another!

The APRS Protocol Specification 1.0.1 at
http://www.tapr.org/tapr/html/Faprswg.html defines time in a number of
formats. Time with a z suffix indicates Zulu time, / indicates local.
Likewise, h format is supposed to be in time Zulu as well.
Month/Day/Hours/Minutes format does not have a designator but is a different
length so can be ID'd and parsed out as Zulu as well.

Each code can be identified, as long as the building application follows the
protocol. Knowing the possible combinations of time formats, a test can be
made to ID the format, then the conversion continue once the format is
picked. I can see where confusion would exist if the sender used local
time...then the receiver may choose to accept it, or hit a config choice
button to ignore times. Of course, this also depends on whether you can
tolerate the minutes of difference that usually comes with many different HT
and PDA clocks all churning out thier vision of current time....but for what
I'm looking at with SAR, we could check each user's timestamping device
before they go out. Devices using GPS time would solve the problem
automatically.
----- Original Message ----- 
From: "kc7zru" <kc7zru at kc7zru.net>
> Steve D (of Findu fame) has commented on this idea a bit over on the
> TAPR SIG. I buy his thinking - unless you know that every station
> origionating a packet is set to the same time standard - the embedded
> times are all but meaningless. It's just the time that particular client
> "thinks" it is - no way to verify. Just way to much variation in times
> to be useful.
>
> However, using the packet received time - even though it may not
> indicate the transmitted time - at least gives you a valid, relative
> metric. AND, if you know your PC is set right (using ntp or similar),
> well, that's as good as it gets.
>
> At the least - a consideration to work about the room a bit.
>
> 73