NTPsec

rabbit.wiktel.com

Report generated: Tue Oct 6 04:45:01 2026 UTC
Start Time: Tue Sep 29 04:45:00 2026 UTC
End Time: Tue Oct 6 04:45:00 2026 UTC
Report Period: 7.0 days

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Local Clock Time/Frequency Offsets

local offset plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Time Offset -2,341.000 -707.000 -240.000 0.000 239.000 647.000 2,391.000 479.000 1,354.000 198.774 0.064 ns -4.835 37
Local Clock Frequency Offset -17.103 -17.090 -17.044 -16.916 -16.781 -16.728 -16.707 0.263 0.361 0.081 -16.909 ppm -9.173e+06 1.92e+09

The time and frequency offsets between the ntpd calculated time and the local system clock. Showing frequency offset (red, in parts per million, scale on right) and the time offset (blue, in μs, scale on left). Quick changes in time offset will lead to larger frequency offsets.

These are fields 3 (time) and 4 (frequency) from the loopstats log file.



Local RMS Time Jitter

local jitter plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local RMS Time Jitter 0.000 1.000 1.000 1.000 21.000 70.000 296.000 20.000 69.000 13.764 4.780 ns 5.376 68.27

The RMS Jitter of the local clock offset. In other words, how fast the local clock offset is changing.

Lower is better. An ideal system would be a horizontal line at 0μs.

RMS jitter is field 5 in the loopstats log file.



Local RMS Frequency Jitter

local stability plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local RMS Frequency Jitter 0.000 4.000 8.000 38.000 427.000 844.000 2,081.000 419.000 840.000 169.708 95.359 10e-12 2.808 21.15

The RMS Frequency Jitter (aka wander) of the local clock's frequency. In other words, how fast the local clock changes frequency.

Lower is better. An ideal clock would be a horizontal line at 0ppm.

RMS Frequency Jitter is field 6 in the loopstats log file.



Local Clock Time Offset Histogram

local offset histogram plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Offset -2,341.000 -707.000 -240.000 0.000 239.000 647.000 2,391.000 479.000 1,354.000 198.774 0.064 ns -4.835 37

The clock offsets of the local clock as a histogram.

The Local Clock Offset is field 3 from the loopstats log file.



Server Offsets

peer offsets plot

The offset of all refclocks and servers. This can be useful to see if offset changes are happening in a single clock or all clocks together.

Clock Offset is field 5 in the peerstats log file.



Server Offset 2001:678:8::123 (any.time.nl)

peer offset 2001:678:8::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:678:8::123 (any.time.nl) -10.077 -0.884 -0.465 0.142 0.779 1.449 5.367 1.244 2.333 0.595 0.127 ms -8.819 138.9

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2600:2600::199 (ntp2.wiktel.com)

peer offset 2600:2600::199 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2600:2600::199 (ntp2.wiktel.com) -1.157 -1.022 -0.874 -0.473 -0.129 -0.036 0.154 0.745 0.986 0.219 -0.486 ms -43.22 175.5

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2600:2600::99 (ntp1.wiktel.com)

peer offset 2600:2600::99 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2600:2600::99 (ntp1.wiktel.com) -788.463 -644.617 -496.973 -87.951 250.926 344.882 508.401 747.899 989.499 219.169 -106.205 µs -8 22.56

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2602:81c:1000:2::604 (time-usw4.crimpac.net)

peer offset 2602:81c:1000:2::604 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2602:81c:1000:2::604 (time-usw4.crimpac.net) -0.332 -0.165 0.170 0.774 1.199 1.366 1.500 1.029 1.531 0.302 0.745 ms 6.991 17.84

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2606:4700:f1::123 (time.cloudflare.com)

peer offset 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -1,111.759 -923.269 -747.352 -184.124 262.263 379.448 585.890 1,009.615 1,302.717 307.080 -208.508 µs -10.01 28.95

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 50.205.57.38

peer offset 50.205.57.38 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 50.205.57.38 -2.163 -0.253 -0.085 0.319 0.719 1.368 1.659 0.804 1.621 0.295 0.317 ms -0.2951 15.96

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset SHM(0)

peer offset SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(0) -2,342.000 -708.000 -241.000 1.000 240.000 648.000 2,392.000 481.000 1,356.000 199.236 0.077 ns -4.83 36.83

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Jitters

peer jitters plot

The RMS Jitter of all refclocks and servers. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2001:678:8::123 (any.time.nl)

peer jitter 2001:678:8::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:678:8::123 (any.time.nl) 0.018 0.034 0.046 0.125 0.584 2.298 5.892 0.538 2.264 0.427 0.223 ms 6.446 68.7

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2600:2600::199 (ntp2.wiktel.com)

peer jitter 2600:2600::199 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2600:2600::199 (ntp2.wiktel.com) 16.831 25.627 33.010 61.042 112.066 137.928 376.168 79.056 112.301 26.999 65.547 µs 9.946 57.49

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2600:2600::99 (ntp1.wiktel.com)

peer jitter 2600:2600::99 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2600:2600::99 (ntp1.wiktel.com) 10.538 16.308 22.567 42.895 83.988 108.861 152.715 61.421 92.553 18.939 46.345 µs 8.602 29.25

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2602:81c:1000:2::604 (time-usw4.crimpac.net)

peer jitter 2602:81c:1000:2::604 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2602:81c:1000:2::604 (time-usw4.crimpac.net) 0.015 0.025 0.033 0.064 0.141 0.292 19.751 0.107 0.267 0.435 0.085 ms 41.41 1867

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2606:4700:f1::123 (time.cloudflare.com)

peer jitter 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 15.592 25.608 34.330 66.403 315.240 415.134 1,473.727 280.910 389.526 88.049 93.862 µs 4.337 39.66

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 50.205.57.38

peer jitter 50.205.57.38 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 50.205.57.38 0.017 0.024 0.033 0.059 0.115 0.152 47.109 0.082 0.129 2.014 0.159 ms 19.11 438.9

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter SHM(0)

peer jitter SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(0) 0.000 0.000 1.000 2.000 46.000 227.000 1,565.000 45.000 227.000 52.577 13.473 ns 9.028 162.2

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -17.103 -17.090 -17.044 -16.916 -16.781 -16.728 -16.707 0.263 0.361 0.081 -16.909 ppm -9.173e+06 1.92e+09
Local Clock Time Offset -2,341.000 -707.000 -240.000 0.000 239.000 647.000 2,391.000 479.000 1,354.000 198.774 0.064 ns -4.835 37
Local RMS Frequency Jitter 0.000 4.000 8.000 38.000 427.000 844.000 2,081.000 419.000 840.000 169.708 95.359 10e-12 2.808 21.15
Local RMS Time Jitter 0.000 1.000 1.000 1.000 21.000 70.000 296.000 20.000 69.000 13.764 4.780 ns 5.376 68.27
Server Jitter 2001:678:8::123 (any.time.nl) 0.018 0.034 0.046 0.125 0.584 2.298 5.892 0.538 2.264 0.427 0.223 ms 6.446 68.7
Server Jitter 2600:2600::199 (ntp2.wiktel.com) 16.831 25.627 33.010 61.042 112.066 137.928 376.168 79.056 112.301 26.999 65.547 µs 9.946 57.49
Server Jitter 2600:2600::99 (ntp1.wiktel.com) 10.538 16.308 22.567 42.895 83.988 108.861 152.715 61.421 92.553 18.939 46.345 µs 8.602 29.25
Server Jitter 2602:81c:1000:2::604 (time-usw4.crimpac.net) 0.015 0.025 0.033 0.064 0.141 0.292 19.751 0.107 0.267 0.435 0.085 ms 41.41 1867
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 15.592 25.608 34.330 66.403 315.240 415.134 1,473.727 280.910 389.526 88.049 93.862 µs 4.337 39.66
Server Jitter 50.205.57.38 0.017 0.024 0.033 0.059 0.115 0.152 47.109 0.082 0.129 2.014 0.159 ms 19.11 438.9
Server Jitter SHM(0) 0.000 0.000 1.000 2.000 46.000 227.000 1,565.000 45.000 227.000 52.577 13.473 ns 9.028 162.2
Server Offset 2001:678:8::123 (any.time.nl) -10.077 -0.884 -0.465 0.142 0.779 1.449 5.367 1.244 2.333 0.595 0.127 ms -8.819 138.9
Server Offset 2600:2600::199 (ntp2.wiktel.com) -1.157 -1.022 -0.874 -0.473 -0.129 -0.036 0.154 0.745 0.986 0.219 -0.486 ms -43.22 175.5
Server Offset 2600:2600::99 (ntp1.wiktel.com) -788.463 -644.617 -496.973 -87.951 250.926 344.882 508.401 747.899 989.499 219.169 -106.205 µs -8 22.56
Server Offset 2602:81c:1000:2::604 (time-usw4.crimpac.net) -0.332 -0.165 0.170 0.774 1.199 1.366 1.500 1.029 1.531 0.302 0.745 ms 6.991 17.84
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -1,111.759 -923.269 -747.352 -184.124 262.263 379.448 585.890 1,009.615 1,302.717 307.080 -208.508 µs -10.01 28.95
Server Offset 50.205.57.38 -2.163 -0.253 -0.085 0.319 0.719 1.368 1.659 0.804 1.621 0.295 0.317 ms -0.2951 15.96
Server Offset SHM(0) -2,342.000 -708.000 -241.000 1.000 240.000 648.000 2,392.000 481.000 1,356.000 199.236 0.077 ns -4.83 36.83
Summary as CSV file


Glossary:

frequency offset:
The difference between the ntpd calculated frequency and the local system clock frequency (usually in parts per million, ppm)
jitter, dispersion:
The short term change in a value. NTP measures Local Time Jitter, Refclock Jitter, and Server Jitter in seconds. Local Frequency Jitter is in ppm or ppb.
kurtosis, Kurt:
The kurtosis of a random variable X is the fourth standardized moment and is a dimension-less ratio. ntpviz uses the Pearson's moment coefficient of kurtosis. A normal distribution has a kurtosis of three. NIST describes a kurtosis over three as "heavy tailed" and one under three as "light tailed".
ms, millisecond:
One thousandth of a second = 0.001 seconds, 1e-3 seconds
mu, mean:
The arithmetic mean: the sum of all the values divided by the number of values. The formula for mu is: "mu = (∑xi) / N". Where xi denotes the data points and N is the number of data points.
ns, nanosecond:
One billionth of a second, also one thousandth of a microsecond, 0.000000001 seconds and 1e-9 seconds.
percentile:
The value below which a given percentage of values fall.
ppb, parts per billion:
Ratio between two values. These following are all the same: 1 ppb, one in one billion, 1/1,000,000,000, 0.000,000,001, 1e-9 and 0.000,000,1%
ppm, parts per million:
Ratio between two values. These following are all the same: 1 ppm, one in one million, 1/1,000,000, 0.000,001, and 0.000,1%
‰, parts per thousand:
Ratio between two values. These following are all the same: 1 ‰. one in one thousand, 1/1,000, 0.001, and 0.1%
refclock:
Reference clock, a local GPS module or other local source of time.
remote clock:
Any clock reached over the network, LAN or WAN. Also called a peer or server.
time offset:
The difference between the ntpd calculated time and the local system clock's time. Also called phase offset.
σ, sigma:
Sigma denotes the standard deviation (SD) and is centered on the arithmetic mean of the data set. The SD is simply the square root of the variance of the data set. Two sigma is simply twice the standard deviation. Three sigma is three times sigma. Smaller is better.
The formula for sigma is: "σ = √[ ∑(xi-mu)^2 / N ]". Where xi denotes the data points and N is the number of data points.
skewness, Skew:
The skewness of a random variable X is the third standardized moment and is a dimension-less ratio. ntpviz uses the Pearson's moment coefficient of skewness. Wikipedia describes it best: "The qualitative interpretation of the skew is complicated and unintuitive."
A normal distribution has a skewness of zero.
upstream clock:
Any server or reference clock used as a source of time.
µs, us, microsecond:
One millionth of a second, also one thousandth of a millisecond, 0.000,001 seconds, and 1e-6 seconds.



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