NTPsec

ntp1.wiktel.com

Report generated: Mon Mar 16 07:53:00 2026 UTC
Start Time: Sun Mar 15 07:53:00 2026 UTC
End Time: Mon Mar 16 07:53:00 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 -11.108 -6.589 -4.207 -0.011 4.183 6.958 12.474 8.390 13.547 2.611 -0.016 µs -3.903 10.74
Local Clock Frequency Offset 17.724 17.743 17.773 17.870 17.965 18.004 18.020 0.192 0.261 0.057 17.868 ppm 3.102e+07 9.748e+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 0.256 0.426 0.507 0.991 2.505 3.078 4.795 1.998 2.652 0.666 1.217 µs 4.073 11.51

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 0.161 0.260 0.379 1.032 2.211 3.282 4.735 1.832 3.022 0.600 1.126 ppb 4.902 18.61

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 -11.108 -6.589 -4.207 -0.011 4.183 6.958 12.474 8.390 13.547 2.611 -0.016 µs -3.903 10.74

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 -462.009 -365.844 -307.170 47.129 120.761 153.619 192.135 427.931 519.463 135.789 -3.095 µs -5.639 17.54

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 -12.893 -4.944 -2.125 1.364 3.331 4.091 4.210 5.457 9.035 1.752 1.122 ms -3.59 21.29

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) -118.952 -106.699 -88.678 -57.576 -28.546 -21.378 -17.089 60.132 85.321 18.010 -58.235 µs -88.82 436.1

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) -213.176 -213.176 -148.389 -31.231 112.453 230.823 230.823 260.842 443.999 74.736 -31.256 µs -6.443 17.79

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) -562.761 -515.172 -469.256 -239.083 152.401 182.324 202.760 621.657 697.496 206.170 -200.447 µs -13.31 38.02

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) -435.922 -433.088 -410.672 -371.461 -318.719 -303.101 -285.840 91.953 129.987 27.720 -368.597 µs -2965 4.3e+04

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) -11.109 -6.590 -4.208 -0.012 4.184 6.959 12.475 8.392 13.549 2.612 -0.016 µs -3.903 10.74

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 5.540 9.289 14.245 50.942 355.667 383.634 423.497 341.422 374.345 138.109 145.855 µs 0.6371 1.579

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 2.098 2.647 4.753 16.554 108.173 167.080 174.414 103.420 164.433 32.735 27.261 ms 2.214 8.644

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) 8.469 10.116 13.950 24.943 42.780 63.175 352.081 28.830 53.059 21.351 27.656 µs 13.31 203

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) 8.696 8.696 14.724 35.350 177.962 394.403 394.403 163.238 385.707 71.650 61.420 µs 2.814 12.4

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) 10.076 11.457 16.134 99.245 382.263 499.295 516.704 366.129 487.838 133.061 154.837 µs 1.167 2.775

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) 9.387 11.154 13.294 25.127 47.756 68.842 93.892 34.462 57.688 11.945 27.083 µs 7.569 29.31

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) 0.105 0.282 0.374 0.984 4.926 6.726 8.783 4.552 6.444 1.459 1.598 µs 2.056 6.721

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 17.724 17.743 17.773 17.870 17.965 18.004 18.020 0.192 0.261 0.057 17.868 ppm 3.102e+07 9.748e+09
Local Clock Time Offset -11.108 -6.589 -4.207 -0.011 4.183 6.958 12.474 8.390 13.547 2.611 -0.016 µs -3.903 10.74
Local RMS Frequency Jitter 0.161 0.260 0.379 1.032 2.211 3.282 4.735 1.832 3.022 0.600 1.126 ppb 4.902 18.61
Local RMS Time Jitter 0.256 0.426 0.507 0.991 2.505 3.078 4.795 1.998 2.652 0.666 1.217 µs 4.073 11.51
Server Jitter 128.101.101.101 5.540 9.289 14.245 50.942 355.667 383.634 423.497 341.422 374.345 138.109 145.855 µs 0.6371 1.579
Server Jitter 209.87.233.53 2.098 2.647 4.753 16.554 108.173 167.080 174.414 103.420 164.433 32.735 27.261 ms 2.214 8.644
Server Jitter 2602:fd53:11e:123::2 (time2.mbix.ca) 8.469 10.116 13.950 24.943 42.780 63.175 352.081 28.830 53.059 21.351 27.656 µs 13.31 203
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 8.696 8.696 14.724 35.350 177.962 394.403 394.403 163.238 385.707 71.650 61.420 µs 2.814 12.4
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 10.076 11.457 16.134 99.245 382.263 499.295 516.704 366.129 487.838 133.061 154.837 µs 1.167 2.775
Server Jitter 2607:f388::123:1 (ntp1.doit.wisc.edu) 9.387 11.154 13.294 25.127 47.756 68.842 93.892 34.462 57.688 11.945 27.083 µs 7.569 29.31
Server Jitter PPS(0) 0.105 0.282 0.374 0.984 4.926 6.726 8.783 4.552 6.444 1.459 1.598 µs 2.056 6.721
Server Offset 128.101.101.101 -462.009 -365.844 -307.170 47.129 120.761 153.619 192.135 427.931 519.463 135.789 -3.095 µs -5.639 17.54
Server Offset 209.87.233.53 -12.893 -4.944 -2.125 1.364 3.331 4.091 4.210 5.457 9.035 1.752 1.122 ms -3.59 21.29
Server Offset 2602:fd53:11e:123::2 (time2.mbix.ca) -118.952 -106.699 -88.678 -57.576 -28.546 -21.378 -17.089 60.132 85.321 18.010 -58.235 µs -88.82 436.1
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -213.176 -213.176 -148.389 -31.231 112.453 230.823 230.823 260.842 443.999 74.736 -31.256 µs -6.443 17.79
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -562.761 -515.172 -469.256 -239.083 152.401 182.324 202.760 621.657 697.496 206.170 -200.447 µs -13.31 38.02
Server Offset 2607:f388::123:1 (ntp1.doit.wisc.edu) -435.922 -433.088 -410.672 -371.461 -318.719 -303.101 -285.840 91.953 129.987 27.720 -368.597 µs -2965 4.3e+04
Server Offset PPS(0) -11.109 -6.590 -4.208 -0.012 4.184 6.959 12.475 8.392 13.549 2.612 -0.016 µs -3.903 10.74
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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