NTPsec

rabbit.wiktel.com

Report generated: Wed Apr 8 04:45:01 2026 UTC
Start Time: Wed Apr 1 04:45:00 2026 UTC
End Time: Wed Apr 8 04:45:00 2026 UTC
Report Period: 7.0 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 -2,245.000 -754.000 -250.000 0.000 245.000 747.000 3,614.000 495.000 1,501.000 220.674 0.264 ns -3.296 39.76
Local Clock Frequency Offset -21.641 -21.599 -21.565 -21.491 -21.281 -21.174 -21.048 0.284 0.425 0.088 -21.465 ppm -1.482e+07 3.64e+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 22.000 74.000 474.000 21.000 73.000 15.272 5.013 ns 6.323 97.83

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 3.000 6.000 34.000 439.000 978.000 3,137.000 433.000 975.000 191.587 99.782 10e-12 3.222 29.12

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 -2,245.000 -754.000 -250.000 0.000 245.000 747.000 3,614.000 495.000 1,501.000 220.674 0.264 ns -3.296 39.76

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 -1.351 -1.133 -0.966 -0.530 -0.076 0.390 0.559 0.891 1.523 0.280 -0.535 ms -32.76 119.8

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 -1.660 -1.210 -0.946 -0.449 -0.021 0.386 0.577 0.925 1.597 0.291 -0.459 ms -24.83 87.86

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 -19.845 -6.806 -2.784 -1.927 -1.079 -0.639 0.393 1.705 6.166 1.360 -2.042 ms -31.49 247.6

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 -657.594 -523.863 -119.915 226.936 665.441 767.520 750.799 1,323.035 228.640 -130.092 µs -8.243 23.66

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) -0.480 -0.317 -0.157 0.251 0.599 1.075 1.157 0.756 1.392 0.232 0.241 ms 0.554 5.162

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) -810.714 -610.032 -421.506 39.440 602.961 967.002 1,255.840 1,024.467 1,577.034 311.554 65.594 µs -2.469 6.411

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) -2,246.000 -755.000 -250.000 1.000 246.000 748.000 3,615.000 496.000 1,503.000 221.109 0.294 ns -3.3 39.59

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 0.000 0.028 0.042 0.143 0.629 1.177 2.467 0.586 1.149 0.230 0.222 ms 3.023 18.18

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 0.030 0.041 0.116 1.733 2.470 115.936 1.692 2.439 2.639 0.417 ms 38.83 1699

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 0.256 0.497 0.699 1.296 13.047 76.755 126.391 12.348 76.258 10.925 3.628 ms 4.302 37.52

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) 10.723 18.368 25.197 48.609 88.393 111.905 152.034 63.196 93.537 19.671 51.891 µs 10.26 33.82

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) 11.350 19.191 25.700 50.190 88.295 110.629 140.317 62.595 91.438 19.420 52.865 µs 11.07 36.01

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) 10.427 21.802 32.026 68.790 319.487 403.523 493.353 287.461 381.721 86.973 101.718 µs 2.537 8.126

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 50.000 227.000 2,384.000 49.000 227.000 58.034 13.955 ns 10.24 216.2

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 -21.641 -21.599 -21.565 -21.491 -21.281 -21.174 -21.048 0.284 0.425 0.088 -21.465 ppm -1.482e+07 3.64e+09
Local Clock Time Offset -2,245.000 -754.000 -250.000 0.000 245.000 747.000 3,614.000 495.000 1,501.000 220.674 0.264 ns -3.296 39.76
Local RMS Frequency Jitter 0.000 3.000 6.000 34.000 439.000 978.000 3,137.000 433.000 975.000 191.587 99.782 10e-12 3.222 29.12
Local RMS Time Jitter 0.000 1.000 1.000 1.000 22.000 74.000 474.000 21.000 73.000 15.272 5.013 ns 6.323 97.83
Server Jitter 158.51.99.19 0.000 0.028 0.042 0.143 0.629 1.177 2.467 0.586 1.149 0.230 0.222 ms 3.023 18.18
Server Jitter 23.186.168.126 0.019 0.030 0.041 0.116 1.733 2.470 115.936 1.692 2.439 2.639 0.417 ms 38.83 1699
Server Jitter 24.249.17.252 0.256 0.497 0.699 1.296 13.047 76.755 126.391 12.348 76.258 10.925 3.628 ms 4.302 37.52
Server Jitter 2600:2600::199 (ntp2.wiktel.com) 10.723 18.368 25.197 48.609 88.393 111.905 152.034 63.196 93.537 19.671 51.891 µs 10.26 33.82
Server Jitter 2600:2600::99 (ntp1.wiktel.com) 11.350 19.191 25.700 50.190 88.295 110.629 140.317 62.595 91.438 19.420 52.865 µs 11.07 36.01
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 10.427 21.802 32.026 68.790 319.487 403.523 493.353 287.461 381.721 86.973 101.718 µs 2.537 8.126
Server Jitter SHM(0) 0.000 0.000 1.000 2.000 50.000 227.000 2,384.000 49.000 227.000 58.034 13.955 ns 10.24 216.2
Server Offset 158.51.99.19 -1.351 -1.133 -0.966 -0.530 -0.076 0.390 0.559 0.891 1.523 0.280 -0.535 ms -32.76 119.8
Server Offset 23.186.168.126 -1.660 -1.210 -0.946 -0.449 -0.021 0.386 0.577 0.925 1.597 0.291 -0.459 ms -24.83 87.86
Server Offset 24.249.17.252 -19.845 -6.806 -2.784 -1.927 -1.079 -0.639 0.393 1.705 6.166 1.360 -2.042 ms -31.49 247.6
Server Offset 2600:2600::199 (ntp2.wiktel.com) -856.258 -657.594 -523.863 -119.915 226.936 665.441 767.520 750.799 1,323.035 228.640 -130.092 µs -8.243 23.66
Server Offset 2600:2600::99 (ntp1.wiktel.com) -0.480 -0.317 -0.157 0.251 0.599 1.075 1.157 0.756 1.392 0.232 0.241 ms 0.554 5.162
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -810.714 -610.032 -421.506 39.440 602.961 967.002 1,255.840 1,024.467 1,577.034 311.554 65.594 µs -2.469 6.411
Server Offset SHM(0) -2,246.000 -755.000 -250.000 1.000 246.000 748.000 3,615.000 496.000 1,503.000 221.109 0.294 ns -3.3 39.59
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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