NTPsec

ntp1.wiktel.com

Report generated: Fri Jan 23 13:53:00 2026 UTC
Start Time: Thu Jan 22 13:53:00 2026 UTC
End Time: Fri Jan 23 13:53:00 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 -16.428 -8.016 -5.375 -0.500 8.444 10.855 17.386 13.819 18.871 3.967 -0.022 µs -3.214 7.889
Local Clock Frequency Offset 17.449 17.540 17.580 17.759 17.882 17.983 18.021 0.302 0.443 0.102 17.746 ppm 5.186e+06 8.976e+08

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 0.294 0.377 0.455 0.781 2.455 3.133 5.253 2.000 2.756 0.658 1.071 µs 3.584 10.95

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 0.142 0.186 0.254 1.324 4.087 5.082 6.410 3.833 4.896 1.145 1.563 ppb 2.391 7.02

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 -16.428 -8.016 -5.375 -0.500 8.444 10.855 17.386 13.819 18.871 3.967 -0.022 µs -3.214 7.889

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 128.101.101.101

peer offset 128.101.101.101 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 128.101.101.101 -954.744 -819.959 -762.078 -374.699 111.378 185.978 228.916 873.456 1,005.937 305.586 -359.921 µs -16.65 50.94

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 209.87.233.53

peer offset 209.87.233.53 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 209.87.233.53 -5.437 -4.472 -2.297 1.710 4.587 5.883 8.889 6.884 10.356 2.034 1.468 ms -1.386 5.43

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:fd53:11e:123::2 (time2.mbix.ca)

peer offset 2602:fd53:11e:123::2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2602:fd53:11e:123::2 (time2.mbix.ca) -109.880 -101.790 -90.694 -58.392 -26.917 -17.103 -14.005 63.777 84.687 18.418 -59.923 µs -89.68 438

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::1 (time.cloudflare.com)

peer offset 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -358.460 -358.460 -341.493 -61.308 87.548 116.756 116.756 429.041 475.216 98.771 -67.872 µs -10.75 35.68

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) -245.295 -234.326 -174.236 -53.426 119.840 165.346 200.746 294.076 399.672 91.135 -45.909 µs -7.498 19.02

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 2607:f388::123:1 (ntp1.doit.wisc.edu)

peer offset 2607:f388::123:1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:f388::123:1 (ntp1.doit.wisc.edu) -403.363 -393.099 -377.677 -76.003 2.479 36.463 48.177 380.156 429.562 141.222 -148.404 µs -15.4 49.75

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 PPS(0)

peer offset PPS(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset PPS(0) -16.429 -8.017 -5.375 -0.500 8.445 10.856 17.387 13.820 18.873 3.968 -0.022 µs -3.214 7.889

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 128.101.101.101

peer jitter 128.101.101.101 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 128.101.101.101 6.861 8.482 12.378 54.366 361.178 422.988 702.408 348.800 414.506 140.940 147.961 µs 0.8386 2.7

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 209.87.233.53

peer jitter 209.87.233.53 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 209.87.233.53 2.182 2.582 4.727 14.138 44.107 222.301 222.834 39.380 219.719 26.735 19.772 ms 4.757 33.76

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:fd53:11e:123::2 (time2.mbix.ca)

peer jitter 2602:fd53:11e:123::2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2602:fd53:11e:123::2 (time2.mbix.ca) 10.424 12.692 15.288 25.085 45.913 55.928 59.526 30.625 43.236 9.205 27.215 µs 14.33 49.12

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::1 (time.cloudflare.com)

peer jitter 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 10.036 10.036 14.131 34.633 303.277 386.512 386.512 289.146 376.476 98.653 84.469 µs 1.165 3.444

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) 11.007 12.220 15.292 42.668 157.413 230.026 281.215 142.121 217.806 49.764 59.642 µs 2.403 8.193

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 2607:f388::123:1 (ntp1.doit.wisc.edu)

peer jitter 2607:f388::123:1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:f388::123:1 (ntp1.doit.wisc.edu) 9.356 10.454 13.579 23.386 45.589 162.078 318.588 32.010 151.624 24.645 27.558 µs 9.025 95.89

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 PPS(0)

peer jitter PPS(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter PPS(0) 0.098 0.248 0.356 0.870 4.791 7.045 13.426 4.435 6.797 1.453 1.463 µs 2.219 8.324

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 17.449 17.540 17.580 17.759 17.882 17.983 18.021 0.302 0.443 0.102 17.746 ppm 5.186e+06 8.976e+08
Local Clock Time Offset -16.428 -8.016 -5.375 -0.500 8.444 10.855 17.386 13.819 18.871 3.967 -0.022 µs -3.214 7.889
Local RMS Frequency Jitter 0.142 0.186 0.254 1.324 4.087 5.082 6.410 3.833 4.896 1.145 1.563 ppb 2.391 7.02
Local RMS Time Jitter 0.294 0.377 0.455 0.781 2.455 3.133 5.253 2.000 2.756 0.658 1.071 µs 3.584 10.95
Server Jitter 128.101.101.101 6.861 8.482 12.378 54.366 361.178 422.988 702.408 348.800 414.506 140.940 147.961 µs 0.8386 2.7
Server Jitter 209.87.233.53 2.182 2.582 4.727 14.138 44.107 222.301 222.834 39.380 219.719 26.735 19.772 ms 4.757 33.76
Server Jitter 2602:fd53:11e:123::2 (time2.mbix.ca) 10.424 12.692 15.288 25.085 45.913 55.928 59.526 30.625 43.236 9.205 27.215 µs 14.33 49.12
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 10.036 10.036 14.131 34.633 303.277 386.512 386.512 289.146 376.476 98.653 84.469 µs 1.165 3.444
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 11.007 12.220 15.292 42.668 157.413 230.026 281.215 142.121 217.806 49.764 59.642 µs 2.403 8.193
Server Jitter 2607:f388::123:1 (ntp1.doit.wisc.edu) 9.356 10.454 13.579 23.386 45.589 162.078 318.588 32.010 151.624 24.645 27.558 µs 9.025 95.89
Server Jitter PPS(0) 0.098 0.248 0.356 0.870 4.791 7.045 13.426 4.435 6.797 1.453 1.463 µs 2.219 8.324
Server Offset 128.101.101.101 -954.744 -819.959 -762.078 -374.699 111.378 185.978 228.916 873.456 1,005.937 305.586 -359.921 µs -16.65 50.94
Server Offset 209.87.233.53 -5.437 -4.472 -2.297 1.710 4.587 5.883 8.889 6.884 10.356 2.034 1.468 ms -1.386 5.43
Server Offset 2602:fd53:11e:123::2 (time2.mbix.ca) -109.880 -101.790 -90.694 -58.392 -26.917 -17.103 -14.005 63.777 84.687 18.418 -59.923 µs -89.68 438
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -358.460 -358.460 -341.493 -61.308 87.548 116.756 116.756 429.041 475.216 98.771 -67.872 µs -10.75 35.68
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -245.295 -234.326 -174.236 -53.426 119.840 165.346 200.746 294.076 399.672 91.135 -45.909 µs -7.498 19.02
Server Offset 2607:f388::123:1 (ntp1.doit.wisc.edu) -403.363 -393.099 -377.677 -76.003 2.479 36.463 48.177 380.156 429.562 141.222 -148.404 µs -15.4 49.75
Server Offset PPS(0) -16.429 -8.017 -5.375 -0.500 8.445 10.856 17.387 13.820 18.873 3.968 -0.022 µs -3.214 7.889
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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