Time Stamp Field in Header

Protocol Version: 3.0
Release Date: January 20, 2017

Timestamp field summary

Big Endian format: bits numbered in big-endian fashion from 0 starting at the left, or high-order, position.
Seconds and fraction of seconds: timestamps are represented as a 64-bit unsigned fixed-point number, in seconds relative to 00:00:00 January 1, 1970, UTC. The integer part is in the first 32 bits (Unix-style timestamp) and the fraction part in the last 32 bits. In the fraction part, the non-significant low order can be set to 0.
Wrap around: The first 32-bit field will overflow some time in 2106 (second 4,294,967,296)

Obtaining timestamp

itk::RealTimeClock
Linux / Mac: ftime()
Windows: ftime() - 10 ms resolution
Old Timestamp - 1 sec resoultion: Now, Time, Timer
System time - 10 msec resolution: GetTickCount, GetTickCount64 or timeGetTime()
Highres - hardware dependent: QueryPerformanceCounter (Intel IA32 instruction: RDTSC)

Time synchronization

Two solutions: 0. Install NTP on all devices 0. Compute timestamp differences (local NTP can be used)

Resources

NTP4 Timestamp: RFC 2030 and RFC 1305. (See "3. NTP Timestamp Format")
Obtaining Accurate Timestamps under Windows XP