
buscq9421
-Interested User-
Posts: 10
Joined: Jan 26, 2019
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Posted: Feb 12, 2019 11:00 AM

Msg. 1 of 5
I am trying to calculate the delay from my local_time to IQFeed's server_time.
Right after I receive a Q message whose message content contains "b" or "a", I logging my local_time. The Bid Time or Ask Time in the Q message provides the server_time.
I expect local_time - server_time to be some small positive number, but I notice it's pretty consistently around -0.55 seconds. Hence, I wonder if IQFeed offers some good way for local machine to align to the server time.
Thanks.
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quickTick
-Interested User-
Posts: 53
Joined: Nov 17, 2013
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Posted: Feb 12, 2019 11:31 AM

Msg. 2 of 5
There are 'T' messages giving you the server time each second. I haven't tried to use them to synch yet, however I would assume they are sent at each full second.
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stargrazer
-DTN Guru-
Posts: 302
Joined: Jun 13, 2005
Right Here & Now
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Posted: Feb 12, 2019 12:57 PM

Msg. 3 of 5
Do you use NTP to sync the time of your server to the 'rest of the world'?
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quickTick
-Interested User-
Posts: 53
Joined: Nov 17, 2013
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Posted: Feb 12, 2019 02:26 PM

Msg. 4 of 5
A quick test: the difference between local NTP time and "T" server time indicates "T" time has a small delay in addition to half of ping roundtrip. Symbols from Chicago have another, yet small, delay on top of that, and symbols from New York a bit higher delay. As far as I can tell, nothing strange or unexpected.
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stargrazer
-DTN Guru-
Posts: 302
Joined: Jun 13, 2005
Right Here & Now
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Posted: Feb 12, 2019 02:33 PM

Msg. 5 of 5
I'm not sure what the question is, because I think the discrepancies can be attributed to mostly physics then.
When I looked at this many moons ago, Chicago was closer then NY to the DTN servers, thus the differences in time.
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