How to get timestamp of tick precision in .NET / C#?

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Up until now I used DateTime.Now for getting timestamps, but I noticed that if you print DateTime.Now in a loop you will see that it increments in descrete jumps of approx. 15 ms. But for certain scenarios in my application I need to get the most accurate timestamp possible, preferably with tick (=100 ns) precision. Any ideas?

Update:

Apparently, StopWatch / QueryPerformanceCounter is the way to go, but it can only be used to measure time, so I was thinking about calling DateTime.Now when the application starts up and then just have StopWatch run and then just add the elapsed time from StopWatch to the initial value returned from DateTime.Now. At least that should give me accurate relative timestamps, right? What do you think about that (hack)?

NOTE:

StopWatch.ElapsedTicks is different from StopWatch.Elapsed.Ticks! I used the former assuming 1 tick = 100 ns, but in this case 1 tick = 1 / StopWatch.Frequency. So to get ticks equivalent to DateTime use StopWatch.Elapsed.Ticks. I just learned this the hard way.

NOTE 2:

Using the StopWatch approach, I noticed it gets out of sync with the real time. After about 10 hours, it was ahead by 5 seconds. So I guess one would have to resync it every X or so where X could be 1 hour, 30 min, 15 min, etc. I am not sure what the optimal timespan for resyncing would be since every resync will change the offset which can be up to 20 ms.

timestamp .net c#
11 Answers

This is too much work for something so simple. Just insert a DateTime in your database with the trade. Then to obtain trade order use your identity column which should be an incrementing value.

If you are inserting into multiple databases and trying to reconcile after the fact then you will be mis-calculating trade order due to any slight variance in your database times (even ns increments as you said)

To solve the multiple database issue you could expose a single service that each trade hits to get an order. The service could return a DateTime.UtcNow.Ticks and an incrementing trade number.

Even using one of the solutions above anyone conducting trades from a location on the network with more latency could possibly place trades first (real world), but they get entered in the wrong order due to latency. Because of this the trade must be considered placed at the database, not at users' consoles.

user_5573710

I think this is the best way to solve this issue:

long timestamp = DateTimeOffset.Now.ToUnixTimeMilliseconds();
user_108265080
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