NTPsec

ntp1.wiktel.com

Report generated: Sun Mar 29 04:45:02 2026 UTC
Start Time: Sun Mar 22 04:45:01 2026 UTC
End Time: Sun Mar 29 04:45:01 2026 UTC
Report Period: 7.0 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 -12.222 -2.579 -1.516 -0.100 2.075 4.804 6.872 3.591 7.383 1.228 -0.002 µs -2.79 11.29
Local Clock Frequency Offset 17.623 17.639 17.655 17.719 17.844 17.878 17.901 0.190 0.239 0.056 17.730 ppm 3.215e+07 1.022e+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 0.270 0.403 0.468 0.683 1.599 2.280 6.389 1.131 1.877 0.379 0.795 µs 7.442 36.59

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 0.118 0.178 0.208 0.352 1.159 2.242 2.855 0.951 2.064 0.372 0.471 ppb 3.994 18.24

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 -12.222 -2.579 -1.516 -0.100 2.075 4.804 6.872 3.591 7.383 1.228 -0.002 µs -2.79 11.29

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 -392.728 -352.017 -310.785 40.089 102.060 133.827 186.692 412.845 485.844 127.873 -4.270 µs -5.911 19.12

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 209.87.233.54

peer offset 209.87.233.54 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 209.87.233.54 -17.146 -5.995 -2.245 1.482 3.692 4.890 15.643 5.937 10.885 1.995 1.241 ms -2.977 18.18

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) -123.549 -102.492 -84.742 -47.701 -20.258 -11.291 -3.257 64.484 91.201 19.792 -49.738 µs -54.32 235.3

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) -307.778 -223.782 -160.346 -17.736 122.531 218.953 614.772 282.877 442.735 89.300 -19.880 µs -4.703 15.22

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) -1.934 -1.810 -0.528 -0.136 0.105 0.155 0.220 0.633 1.965 0.367 -0.234 ms -12.07 53.58

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) -601.382 -538.725 -413.164 -353.274 -283.845 -126.968 -60.616 129.319 411.757 52.831 -351.338 µs -469.8 3760

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) -12.223 -2.580 -1.517 -0.101 2.076 4.805 6.873 3.593 7.385 1.228 -0.002 µs -2.792 11.28

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 4.445 8.624 12.347 47.778 361.166 380.158 419.928 348.819 371.534 143.799 154.120 µs 0.533 1.398

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 209.87.233.54

peer jitter 209.87.233.54 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 209.87.233.54 1.688 3.090 4.890 13.150 85.201 191.492 282.240 80.311 188.402 33.703 22.592 ms 3.137 17.68

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) 2.787 10.277 13.364 25.736 46.377 57.389 261.222 33.013 47.112 11.533 27.262 µs 11.33 125.4

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::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) 5.462 9.560 13.922 37.136 182.708 321.488 718.948 168.786 311.928 63.018 59.023 µs 3.709 26.92

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) 0.005 0.011 0.016 0.099 0.390 0.502 55.847 0.374 0.491 3.042 0.334 ms 13.99 248.2

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.



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) 0.006 0.010 0.013 0.025 0.057 1.410 70.246 0.044 1.400 4.384 0.382 ms 9.52 133.9

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) 0.097 0.257 0.338 0.639 1.726 3.014 11.711 1.388 2.757 0.534 0.782 µs 5.4 38.87

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 17.623 17.639 17.655 17.719 17.844 17.878 17.901 0.190 0.239 0.056 17.730 ppm 3.215e+07 1.022e+10
Local Clock Time Offset -12.222 -2.579 -1.516 -0.100 2.075 4.804 6.872 3.591 7.383 1.228 -0.002 µs -2.79 11.29
Local RMS Frequency Jitter 0.118 0.178 0.208 0.352 1.159 2.242 2.855 0.951 2.064 0.372 0.471 ppb 3.994 18.24
Local RMS Time Jitter 0.270 0.403 0.468 0.683 1.599 2.280 6.389 1.131 1.877 0.379 0.795 µs 7.442 36.59
Server Jitter 128.101.101.101 4.445 8.624 12.347 47.778 361.166 380.158 419.928 348.819 371.534 143.799 154.120 µs 0.533 1.398
Server Jitter 209.87.233.54 1.688 3.090 4.890 13.150 85.201 191.492 282.240 80.311 188.402 33.703 22.592 ms 3.137 17.68
Server Jitter 2602:fd53:11e:123::2 (time2.mbix.ca) 2.787 10.277 13.364 25.736 46.377 57.389 261.222 33.013 47.112 11.533 27.262 µs 11.33 125.4
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 5.462 9.560 13.922 37.136 182.708 321.488 718.948 168.786 311.928 63.018 59.023 µs 3.709 26.92
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.005 0.011 0.016 0.099 0.390 0.502 55.847 0.374 0.491 3.042 0.334 ms 13.99 248.2
Server Jitter 2607:f388::123:1 (ntp1.doit.wisc.edu) 0.006 0.010 0.013 0.025 0.057 1.410 70.246 0.044 1.400 4.384 0.382 ms 9.52 133.9
Server Jitter PPS(0) 0.097 0.257 0.338 0.639 1.726 3.014 11.711 1.388 2.757 0.534 0.782 µs 5.4 38.87
Server Offset 128.101.101.101 -392.728 -352.017 -310.785 40.089 102.060 133.827 186.692 412.845 485.844 127.873 -4.270 µs -5.911 19.12
Server Offset 209.87.233.54 -17.146 -5.995 -2.245 1.482 3.692 4.890 15.643 5.937 10.885 1.995 1.241 ms -2.977 18.18
Server Offset 2602:fd53:11e:123::2 (time2.mbix.ca) -123.549 -102.492 -84.742 -47.701 -20.258 -11.291 -3.257 64.484 91.201 19.792 -49.738 µs -54.32 235.3
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -307.778 -223.782 -160.346 -17.736 122.531 218.953 614.772 282.877 442.735 89.300 -19.880 µs -4.703 15.22
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -1.934 -1.810 -0.528 -0.136 0.105 0.155 0.220 0.633 1.965 0.367 -0.234 ms -12.07 53.58
Server Offset 2607:f388::123:1 (ntp1.doit.wisc.edu) -601.382 -538.725 -413.164 -353.274 -283.845 -126.968 -60.616 129.319 411.757 52.831 -351.338 µs -469.8 3760
Server Offset PPS(0) -12.223 -2.580 -1.517 -0.101 2.076 4.805 6.873 3.593 7.385 1.228 -0.002 µs -2.792 11.28
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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