NTPsec

rabbit.wiktel.com

Report generated: Sun Jun 7 05:53:01 2026 UTC
Start Time: Sat Jun 6 05:53:01 2026 UTC
End Time: Sun Jun 7 05:53:01 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 -1,989.000 -752.000 -316.000 2.000 244.000 561.000 1,172.000 560.000 1,313.000 194.089 -4.057 ns -5.706 32.63
Local Clock Frequency Offset -17.980 -17.971 -17.902 -17.791 -17.717 -17.709 -17.706 0.185 0.261 0.059 -17.801 ppm -2.749e+07 8.297e+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 24.000 73.000 257.000 23.000 72.000 13.557 5.089 ns 4.305 49.16

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 2.000 5.000 8.000 38.000 449.000 775.000 1,711.000 441.000 770.000 161.597 100.357 10e-12 2.229 15.14

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 -1,989.000 -752.000 -316.000 2.000 244.000 561.000 1,172.000 560.000 1,313.000 194.089 -4.057 ns -5.706 32.63

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 2001:559:2be:3::1001

peer offset 2001:559:2be:3::1001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:559:2be:3::1001 0.298 0.313 0.360 0.781 3.612 3.832 3.847 3.251 3.519 1.262 1.437 ms 1.34 2.588

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 23.159.16.194

peer offset 23.159.16.194 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 23.159.16.194 0.504 0.521 0.572 0.985 3.904 4.060 4.107 3.332 3.540 1.315 1.748 ms 1.764 3.283

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) -959.809 -911.611 -840.297 -451.169 -102.181 -51.717 -21.805 738.116 859.894 223.342 -462.506 µs -38.29 149.2

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) -623.215 -579.944 -466.130 -85.083 259.055 307.452 359.111 725.185 887.396 221.254 -100.873 µs -7.593 20.24

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 2600:4040:e0eb:ea00::cbb9:201a

peer offset 2600:4040:e0eb:ea00::cbb9:201a plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2600:4040:e0eb:ea00::cbb9:201a -898.590 -798.275 -691.447 -151.343 511.797 573.839 610.039 1,203.244 1,372.114 344.140 -127.933 µs -6.579 16.49

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) -945.671 -915.386 -831.235 -418.260 -101.540 -45.698 -0.121 729.695 869.688 225.604 -438.666 µs -34.64 132.7

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) -1,990.000 -753.000 -317.000 3.000 245.000 562.000 1,173.000 562.000 1,315.000 194.587 -4.014 ns -5.696 32.48

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 2001:559:2be:3::1001

peer jitter 2001:559:2be:3::1001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:559:2be:3::1001 0.006 0.010 0.014 0.032 0.072 2.805 3.025 0.058 2.795 0.389 0.096 ms 3.756 28.5

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 23.159.16.194

peer jitter 23.159.16.194 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 23.159.16.194 0.033 0.036 0.053 0.148 0.689 3.858 5.634 0.636 3.822 0.573 0.287 ms 4.229 32.86

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) 4.087 8.638 11.546 28.427 67.295 85.281 101.707 55.749 76.643 17.201 32.242 µs 4.451 13.63

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) 8.374 9.822 14.181 32.435 73.112 99.215 194.977 58.931 89.393 19.845 36.360 µs 5.638 30.39

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 2600:4040:e0eb:ea00::cbb9:201a

peer jitter 2600:4040:e0eb:ea00::cbb9:201a plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2600:4040:e0eb:ea00::cbb9:201a 0.014 0.019 0.028 0.062 0.348 0.558 9.842 0.320 0.539 0.555 0.137 ms 14.06 245.8

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) 10.609 11.639 15.704 52.166 208.575 339.653 404.758 192.871 328.014 61.005 69.977 µs 2.869 11.99

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 47.000 272.000 1,356.000 46.000 272.000 52.001 14.108 ns 7.433 118.6

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 -17.980 -17.971 -17.902 -17.791 -17.717 -17.709 -17.706 0.185 0.261 0.059 -17.801 ppm -2.749e+07 8.297e+09
Local Clock Time Offset -1,989.000 -752.000 -316.000 2.000 244.000 561.000 1,172.000 560.000 1,313.000 194.089 -4.057 ns -5.706 32.63
Local RMS Frequency Jitter 2.000 5.000 8.000 38.000 449.000 775.000 1,711.000 441.000 770.000 161.597 100.357 10e-12 2.229 15.14
Local RMS Time Jitter 0.000 1.000 1.000 1.000 24.000 73.000 257.000 23.000 72.000 13.557 5.089 ns 4.305 49.16
Server Jitter 2001:559:2be:3::1001 0.006 0.010 0.014 0.032 0.072 2.805 3.025 0.058 2.795 0.389 0.096 ms 3.756 28.5
Server Jitter 23.159.16.194 0.033 0.036 0.053 0.148 0.689 3.858 5.634 0.636 3.822 0.573 0.287 ms 4.229 32.86
Server Jitter 2600:2600::199 (ntp2.wiktel.com) 4.087 8.638 11.546 28.427 67.295 85.281 101.707 55.749 76.643 17.201 32.242 µs 4.451 13.63
Server Jitter 2600:2600::99 (ntp1.wiktel.com) 8.374 9.822 14.181 32.435 73.112 99.215 194.977 58.931 89.393 19.845 36.360 µs 5.638 30.39
Server Jitter 2600:4040:e0eb:ea00::cbb9:201a 0.014 0.019 0.028 0.062 0.348 0.558 9.842 0.320 0.539 0.555 0.137 ms 14.06 245.8
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 10.609 11.639 15.704 52.166 208.575 339.653 404.758 192.871 328.014 61.005 69.977 µs 2.869 11.99
Server Jitter SHM(0) 0.000 0.000 1.000 2.000 47.000 272.000 1,356.000 46.000 272.000 52.001 14.108 ns 7.433 118.6
Server Offset 2001:559:2be:3::1001 0.298 0.313 0.360 0.781 3.612 3.832 3.847 3.251 3.519 1.262 1.437 ms 1.34 2.588
Server Offset 23.159.16.194 0.504 0.521 0.572 0.985 3.904 4.060 4.107 3.332 3.540 1.315 1.748 ms 1.764 3.283
Server Offset 2600:2600::199 (ntp2.wiktel.com) -959.809 -911.611 -840.297 -451.169 -102.181 -51.717 -21.805 738.116 859.894 223.342 -462.506 µs -38.29 149.2
Server Offset 2600:2600::99 (ntp1.wiktel.com) -623.215 -579.944 -466.130 -85.083 259.055 307.452 359.111 725.185 887.396 221.254 -100.873 µs -7.593 20.24
Server Offset 2600:4040:e0eb:ea00::cbb9:201a -898.590 -798.275 -691.447 -151.343 511.797 573.839 610.039 1,203.244 1,372.114 344.140 -127.933 µs -6.579 16.49
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -945.671 -915.386 -831.235 -418.260 -101.540 -45.698 -0.121 729.695 869.688 225.604 -438.666 µs -34.64 132.7
Server Offset SHM(0) -1,990.000 -753.000 -317.000 3.000 245.000 562.000 1,173.000 562.000 1,315.000 194.587 -4.014 ns -5.696 32.48
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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