NTPsec

ntp1.wiktel.com

Report generated: Fri May 29 19:53:02 2026 UTC
Start Time: Thu May 28 19:53:01 2026 UTC
End Time: Fri May 29 19:53:01 2026 UTC
Report Period: 1.0 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 -7.067 -2.795 -1.925 -0.168 2.298 3.597 5.762 4.223 6.392 1.332 -0.011 µs -3.673 9.406
Local Clock Frequency Offset 17.477 17.494 17.515 17.614 17.647 17.657 17.664 0.132 0.163 0.042 17.596 ppm 7.21e+07 3.001e+10

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 0.216 0.312 0.389 0.626 1.065 1.775 3.250 0.676 1.463 0.256 0.669 µs 11.95 59.13

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 0.163 0.241 0.283 0.502 1.188 1.648 2.423 0.905 1.407 0.293 0.581 ppb 5.87 22.73

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 -7.067 -2.795 -1.925 -0.168 2.298 3.597 5.762 4.223 6.392 1.332 -0.011 µs -3.673 9.406

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 -370.400 -335.588 -308.502 35.646 83.321 105.927 142.630 391.823 441.515 120.472 -6.980 µs -6.288 21.3

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 199.102.46.70

peer offset 199.102.46.70 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 199.102.46.70 -340.012 -326.894 -266.177 81.723 100.855 105.909 110.972 367.032 432.803 116.028 35.430 µs -4.58 15.1

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 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 -6.782 -2.864 -1.126 1.469 3.565 5.910 6.236 4.691 8.775 1.537 1.383 ms -0.8758 6.481

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) -110.987 -98.220 -83.251 -47.162 -23.215 -16.471 -4.379 60.036 81.749 18.194 -49.926 µs -64.23 291.3

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 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) -485.833 -473.404 -436.794 -300.832 -173.445 -98.780 -53.793 263.349 374.624 73.965 -297.408 µs -141.6 789.6

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 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) -399.322 -384.964 -359.505 -7.676 70.635 127.294 157.825 430.140 512.258 143.473 -59.632 µs -8.406 26.71

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) -7.068 -2.796 -1.926 -0.169 2.299 3.598 5.763 4.225 6.394 1.333 -0.011 µs -3.674 9.404

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 3.375 8.346 11.306 32.306 355.750 374.204 386.146 344.444 365.858 139.475 129.090 µs 0.4333 1.421

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 199.102.46.70

peer jitter 199.102.46.70 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 199.102.46.70 8.822 9.779 13.027 31.329 351.517 365.488 375.219 338.490 355.709 139.605 137.193 µs 0.4571 1.383

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 1.276 2.301 4.078 12.465 39.801 61.021 94.193 35.723 58.720 12.161 15.167 ms 3.846 20.15

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) 6.688 10.141 14.191 24.561 45.441 79.743 1,465.063 31.250 69.602 118.651 36.074 µs 9.452 113.1

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) 7.497 10.596 13.550 30.719 129.939 195.721 214.407 116.389 185.125 36.746 44.607 µs 2.65 9.154

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) 10.175 13.073 18.057 56.659 365.639 390.400 401.517 347.582 377.327 142.360 161.486 µs 0.6635 1.498

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) 0.115 0.195 0.296 0.636 1.387 2.150 5.772 1.091 1.955 0.407 0.724 µs 6.192 41.24

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 17.477 17.494 17.515 17.614 17.647 17.657 17.664 0.132 0.163 0.042 17.596 ppm 7.21e+07 3.001e+10
Local Clock Time Offset -7.067 -2.795 -1.925 -0.168 2.298 3.597 5.762 4.223 6.392 1.332 -0.011 µs -3.673 9.406
Local RMS Frequency Jitter 0.163 0.241 0.283 0.502 1.188 1.648 2.423 0.905 1.407 0.293 0.581 ppb 5.87 22.73
Local RMS Time Jitter 0.216 0.312 0.389 0.626 1.065 1.775 3.250 0.676 1.463 0.256 0.669 µs 11.95 59.13
Server Jitter 128.101.101.101 3.375 8.346 11.306 32.306 355.750 374.204 386.146 344.444 365.858 139.475 129.090 µs 0.4333 1.421
Server Jitter 199.102.46.70 8.822 9.779 13.027 31.329 351.517 365.488 375.219 338.490 355.709 139.605 137.193 µs 0.4571 1.383
Server Jitter 209.87.233.53 1.276 2.301 4.078 12.465 39.801 61.021 94.193 35.723 58.720 12.161 15.167 ms 3.846 20.15
Server Jitter 2602:fd53:11e:123::2 (time2.mbix.ca) 6.688 10.141 14.191 24.561 45.441 79.743 1,465.063 31.250 69.602 118.651 36.074 µs 9.452 113.1
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 7.497 10.596 13.550 30.719 129.939 195.721 214.407 116.389 185.125 36.746 44.607 µs 2.65 9.154
Server Jitter 2607:f388::123:1 (ntp1.doit.wisc.edu) 10.175 13.073 18.057 56.659 365.639 390.400 401.517 347.582 377.327 142.360 161.486 µs 0.6635 1.498
Server Jitter PPS(0) 0.115 0.195 0.296 0.636 1.387 2.150 5.772 1.091 1.955 0.407 0.724 µs 6.192 41.24
Server Offset 128.101.101.101 -370.400 -335.588 -308.502 35.646 83.321 105.927 142.630 391.823 441.515 120.472 -6.980 µs -6.288 21.3
Server Offset 199.102.46.70 -340.012 -326.894 -266.177 81.723 100.855 105.909 110.972 367.032 432.803 116.028 35.430 µs -4.58 15.1
Server Offset 209.87.233.53 -6.782 -2.864 -1.126 1.469 3.565 5.910 6.236 4.691 8.775 1.537 1.383 ms -0.8758 6.481
Server Offset 2602:fd53:11e:123::2 (time2.mbix.ca) -110.987 -98.220 -83.251 -47.162 -23.215 -16.471 -4.379 60.036 81.749 18.194 -49.926 µs -64.23 291.3
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -485.833 -473.404 -436.794 -300.832 -173.445 -98.780 -53.793 263.349 374.624 73.965 -297.408 µs -141.6 789.6
Server Offset 2607:f388::123:1 (ntp1.doit.wisc.edu) -399.322 -384.964 -359.505 -7.676 70.635 127.294 157.825 430.140 512.258 143.473 -59.632 µs -8.406 26.71
Server Offset PPS(0) -7.068 -2.796 -1.926 -0.169 2.299 3.598 5.763 4.225 6.394 1.333 -0.011 µs -3.674 9.404
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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