Do any of you have any preferred/favorite apps for synchronizing the clock? I'd be thrilled if I could get as close as possible to the exchange (NASDAQ) clock, but would settle for an accuracy of around even 200ms or worse. Note that I am not colocated. This is for retail trading purposes, so I can match up live activity with downloaded, accurate data.
I use nistime and recommend it highly: http://www.nist.gov/pml/div688/grp40/its.cfm It's free, works well, and has source code if you need that.
I ended up simply changing the default time sync setting in Windows 7. Here are the instructions I found some place on the web: You can alter the time sync via the Registry. Navigate to the following in the Registry: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpClient (SpecialPollInterval) Right click on 'SpecialPollInterval' in the right hand column and select Modify>Decimal. The decimal number is in seconds. I have that value set to 86400 (24 hours). Please backup the Registry beforehand.
You didn't mention what OS you're running, but you should be aware that if you are running Windows and any Java applications (e.g. Interactive Brokers' TWS), starting the Java app throws your system clock off. I am amazed that this problem hasn't been fixed or even discussed much. There is a workaround, but finding instructions that make sense is difficult. I got my system (Win7, 64-bit) patched, but I cannot remember the steps.
best answer I found (after several failed attempts): http://www.pretentiousname.com/timesync/index.html
Let me call that what is it - ignorant bullshit. You can get down below 1ms over the internet. NTP is a VERY good protocol to average out bad ticks and internet latency is quite exact over a definite period of time. Thank heaven the world does not consist of ignorant people only. See, "over the internet" means what? You are aware that the latency from Europe to US is about 125ms? Now you tell me you are not able to sync MORE THAN 10 TIME THE LATENCY? Damn, you live in a cage with fire instead of modern times? For someone with limited programming experience it may be a challenge to sync down below average variance in latency, but even US to EUR you do not vary 1.375 milliseconds around the average latency of 0.125ms. That is comical. And that is US to EUR - if you are same country to the source server you read time from you likely have a less than 15ms latency. NOW things get funny. You tell me you can not sync 100 times as average as the latency? Whow. For example my trading main station has an average hourly skew of 35ms and is kept within an EXTREMELY close tolerance to GPS time by the means of a lot os sync data arriving per second. Up to last week that is US to germany. Sadly the software is not for sale - rented, so to say, for about 800 USD per month. Ok, I get a lot of exchange data on top Nanex just keeps the time in ultra right sync. But seriously, the inability to sync 1.5 seconds is when the programmer was drunk, has nothing to do with the internet. More with a guy trying to program instead of doing what the creator wanted him to do - serve burgers at McDonalds. Standard simple protocol can dome down to some ms OR tell you it can not sync (when multiple latency test vary widely, so any estimate would be a wild guess). http://en.wikipedia.org/wiki/Network_Time_Protocol has some explanations how things work. Just get a "proper" NTP service. The standard windows one is NOT - it is not designed to be accurate, just accurate enough, mostly for active directory to work, where security tickets from the domain controller are valid for 300 seconds, so any skew of less than a minute or so is ok.