NTPsec

rabbit.wiktel.com

Report generated: Wed Apr 8 14:53:01 2026 UTC
Start Time: Tue Apr 7 14:53:01 2026 UTC
End Time: Wed Apr 8 14:53:01 2026 UTC
Report Period: 1.0 days

Top   Daily Stats   Weekly Stats  

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 -2.319 -1.168 -0.342 -0.002 0.427 1.154 2.831 0.769 2.322 0.321 0.009 µs -3.731 25.79
Local Clock Frequency Offset -21.561 -21.542 -21.515 -21.402 -21.238 -21.209 -21.198 0.277 0.333 0.092 -21.386 ppm -1.265e+07 2.946e+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 34.000 122.000 347.000 33.000 121.000 22.131 7.531 ns 4.308 44.19

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 0.001 0.004 0.011 0.063 0.748 1.417 2.466 0.737 1.413 0.273 0.157 ppb 2.283 13.84

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 -2.319 -1.168 -0.342 -0.002 0.427 1.154 2.831 0.769 2.322 0.321 0.009 µs -3.731 25.79

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 158.51.99.19

peer offset 158.51.99.19 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 158.51.99.19 -1.370 -1.309 -1.201 -0.567 -0.077 0.103 0.117 1.124 1.412 0.324 -0.585 ms -30.74 114.3

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 23.186.168.126

peer offset 23.186.168.126 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 23.186.168.126 -1.363 -1.269 -1.085 -0.406 0.178 0.443 0.451 1.263 1.713 0.381 -0.440 ms -16.55 52.62

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 24.249.17.252

peer offset 24.249.17.252 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 24.249.17.252 -9.211 -6.290 -3.297 -1.968 -0.922 -0.422 -0.327 2.376 5.868 0.922 -2.023 ms -44.95 219.2

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) -856.258 -832.103 -789.727 -141.980 381.033 546.266 601.248 1,170.760 1,378.369 346.956 -171.229 µs -7.923 21.36

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) -481.532 -476.227 -424.738 246.630 745.161 899.290 952.320 1,169.899 1,375.517 340.671 211.965 µs -1.431 3.707

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) -776.087 -580.699 -482.069 105.449 619.579 760.886 821.105 1,101.648 1,341.585 349.876 67.423 µs -3.019 6.757

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) -2.320 -1.169 -0.343 -0.003 0.428 1.155 2.832 0.771 2.324 0.322 0.009 µs -3.732 25.73

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 158.51.99.19

peer jitter 158.51.99.19 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 158.51.99.19 0.027 0.033 0.052 0.229 0.678 1.205 1.414 0.626 1.172 0.226 0.290 ms 2.66 10.51

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 23.186.168.126

peer jitter 23.186.168.126 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 23.186.168.126 0.019 0.024 0.036 0.096 1.807 2.556 2.992 1.771 2.532 0.573 0.332 ms 1.415 6.557

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 24.249.17.252

peer jitter 24.249.17.252 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 24.249.17.252 0.312 0.379 0.658 1.357 16.352 79.422 90.401 15.694 79.043 11.851 3.965 ms 3.541 25.42

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) 8.584 15.274 23.067 48.385 89.724 119.402 145.949 66.657 104.128 21.584 51.781 µs 7.919 25.83

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) 14.614 17.509 23.676 49.670 88.886 125.867 134.527 65.210 108.358 20.717 52.598 µs 9.125 29.49

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 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) 13.312 25.987 35.934 82.977 366.208 483.089 551.229 330.274 457.102 99.292 117.559 µs 2.618 8.876

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 3.000 82.000 355.000 1,745.000 81.000 355.000 84.128 21.717 ns 7.478 105.7

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -21.561 -21.542 -21.515 -21.402 -21.238 -21.209 -21.198 0.277 0.333 0.092 -21.386 ppm -1.265e+07 2.946e+09
Local Clock Time Offset -2.319 -1.168 -0.342 -0.002 0.427 1.154 2.831 0.769 2.322 0.321 0.009 µs -3.731 25.79
Local RMS Frequency Jitter 0.001 0.004 0.011 0.063 0.748 1.417 2.466 0.737 1.413 0.273 0.157 ppb 2.283 13.84
Local RMS Time Jitter 0.000 1.000 1.000 1.000 34.000 122.000 347.000 33.000 121.000 22.131 7.531 ns 4.308 44.19
Server Jitter 158.51.99.19 0.027 0.033 0.052 0.229 0.678 1.205 1.414 0.626 1.172 0.226 0.290 ms 2.66 10.51
Server Jitter 23.186.168.126 0.019 0.024 0.036 0.096 1.807 2.556 2.992 1.771 2.532 0.573 0.332 ms 1.415 6.557
Server Jitter 24.249.17.252 0.312 0.379 0.658 1.357 16.352 79.422 90.401 15.694 79.043 11.851 3.965 ms 3.541 25.42
Server Jitter 2600:2600::199 (ntp2.wiktel.com) 8.584 15.274 23.067 48.385 89.724 119.402 145.949 66.657 104.128 21.584 51.781 µs 7.919 25.83
Server Jitter 2600:2600::99 (ntp1.wiktel.com) 14.614 17.509 23.676 49.670 88.886 125.867 134.527 65.210 108.358 20.717 52.598 µs 9.125 29.49
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 13.312 25.987 35.934 82.977 366.208 483.089 551.229 330.274 457.102 99.292 117.559 µs 2.618 8.876
Server Jitter SHM(0) 0.000 0.000 1.000 3.000 82.000 355.000 1,745.000 81.000 355.000 84.128 21.717 ns 7.478 105.7
Server Offset 158.51.99.19 -1.370 -1.309 -1.201 -0.567 -0.077 0.103 0.117 1.124 1.412 0.324 -0.585 ms -30.74 114.3
Server Offset 23.186.168.126 -1.363 -1.269 -1.085 -0.406 0.178 0.443 0.451 1.263 1.713 0.381 -0.440 ms -16.55 52.62
Server Offset 24.249.17.252 -9.211 -6.290 -3.297 -1.968 -0.922 -0.422 -0.327 2.376 5.868 0.922 -2.023 ms -44.95 219.2
Server Offset 2600:2600::199 (ntp2.wiktel.com) -856.258 -832.103 -789.727 -141.980 381.033 546.266 601.248 1,170.760 1,378.369 346.956 -171.229 µs -7.923 21.36
Server Offset 2600:2600::99 (ntp1.wiktel.com) -481.532 -476.227 -424.738 246.630 745.161 899.290 952.320 1,169.899 1,375.517 340.671 211.965 µs -1.431 3.707
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -776.087 -580.699 -482.069 105.449 619.579 760.886 821.105 1,101.648 1,341.585 349.876 67.423 µs -3.019 6.757
Server Offset SHM(0) -2.320 -1.169 -0.343 -0.003 0.428 1.155 2.832 0.771 2.324 0.322 0.009 µs -3.732 25.73
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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