If it's possible, I'd love to be able to pull a timestamp out of a QWD file for my ongoing Quake Team Fortress video capture/archiving project. A careful reading of the Demospecs site (http://www.quakewiki.net/archives/demospecs/qwd/qwd.html) leads me to believe that it's possible, but I haven't been able to figure it out yet. I'll keep working on it, but if anyone's got some insight into the topic, I'd appreciate it. Thanks!

if you convert your .QWD to a .MVD you can use a tool called: MVDPARSER that extracts all information from the game!

http://www.quakeworld.nu/forum/topic/2358/31690/mvd-parser-/
https://github.com/JoakimSoderberg/mvdparser

you can convert QWD to MVD with QWDTOOLS
just Run this command in prompt: qwdtools.exe -c *.qwd

lmpc - little movie processing center does that work directly to text file.
once i decided to get quake player speed (320) measured in km/h i used lmpc to get timestamps ))

Hmm...if this is an example of the MVDParser output:

http://jogi.netdome.biz/parsetext.txt

Then it doesn't actually pull out timestamp information. Oh well, I'll keep digging.

You can get times from mvdparser by modifying code a little, they are somewhere in mvd-> structure, i have it done on my computer at home.. wait a day or dig mvd-> for float *time* fields

I'm not sure what you are after actually. Do you want the time for a specific frame in ingame time? Or are you interested in the time when this demo was recorded?

Such an output is appropriate for you?
dag: 1320.625 -1088.750 256.000 angles: 10.991821 172.397461 time^ 459.231873
griffin: 158.250 -1738.875 83.500 angles: 10.607300 -53.503418 time^ 459.231873
dag: 1339.250 -1086.375 256.000 angles: 15.529175 147.348633 time^ 459.283875
griffin: 173.375 -1759.875 81.750 angles: 11.217041 -60.770874 time^ 459.283875
dag: 1356.500 -1081.750 255.875 angles: 21.692505 107.248535 time^ 459.334869
griffin: 181.875 -1781.625 77.875 angles: 11.002808 -67.478027 time^ 459.334869
dag: 1373.500 -1078.125 254.875 angles: 24.785156 63.385620 time^ 459.384857
griffin: 187.625 -1804.125 72.125 angles: 10.491943 -75.981445 time^ 459.384857
.... 12567 lines per demo ))
mvd->demotime is the field you want in mvdparser.

in a few days i want to add loc info - from what entity to what the player moves, so it would be easier to undestand/ autoanalyze demo. due to real life issues days can become the month become the years. seasons change time passes by

I think I'm mistaken about what the timestamps actually are. I'm interested in something more like a UNIX timestamp (i.e. the exact time when the packet was sent), but it appears that the timestamps in a demo are just timestamps since the demo was started, which isn't what I'm interested in.

I don't think that demos by themselves carry this information. Your best bet would be that the demo includes a recorded match from a recent match mod. In that case you may be in luck that the mod prints out a match key or match date or similar at the beginning or the end of the match which would be recorded also by the client who recorded the qwd file. With this information and the time deltas of each you frame you can translate every frame to its unique timestamp if desired.

See: http://www.quakeworld.nu/forum/topic/721/please-explain-matchkey

As Tuna says.

FPS is known, so just keep count of number of frames passed and you'll have your timestamp.