Amazon Time Sync is now available over the internet as a public NTP service
Here is a bit of a comparison with these three NTP servers in a &#x2F;etc&#x2F;chrony.conf<p><pre><code>  pool time.aws.com iburst
  pool 1.amazon.pool.ntp.org iburst
  pool time.nist.gov iburst

  # chronyc sourcestats 
  Name&#x2F;IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
  ==============================================================================
  ec2-54-86-189-11.compute&gt;   4   3     7  -1128.596  60538.254    -17ms  9310us
  ec2-18-212-174-188.compu&gt;   4   3     7  -3475.306  40696.289    -32ms  7334us
  ec2-54-224-100-122.compu&gt;   4   3     7  -2748.130  71563.352    -26ms    11ms
  ec2-3-80-167-198.compute&gt;   4   3     7   +827.953  78440.828  +1398us    12ms
  38.229.57.9                 4   4     7   +744.719  67529.711   +117us  9384us
  time.cloudflare.com         4   3     7   +957.450  44361.117  +3899us  6424us
  3dhomejoe.com               4   3     9   -958.576  43000.809    -14ms  7052us
  shed.galexander.org         4   4     7  -4034.244  62138.637    -36ms    10ms
  time-a-b.nist.gov           4   4     7  +1475.911  50544.457  +9056us  5773us

  # chronyc sources
  MS Name&#x2F;IP address         Stratum Poll Reach LastRx Last sample
  ===============================================================================
  ^- ec2-54-86-189-11.compute&gt;     4   6    17    19  -5776us[-5776us] +&#x2F;-   76ms
  ^- ec2-18-212-174-188.compu&gt;     4   6    17    20    -22ms[  -22ms] +&#x2F;-   57ms
  ^- ec2-54-224-100-122.compu&gt;     4   6    17    21  -1057us[-1057us] +&#x2F;-   77ms
  ^- ec2-3-80-167-198.compute&gt;     4   6    17    21  +2093us[+2093us] +&#x2F;-   57ms
  ^- 38.229.57.9                   2   6    17    21   -769us[ -769us] +&#x2F;-  185ms
  ^\* time.cloudflare.com           3   6    17    22  -2043us[+3354us] +&#x2F;-   34ms
  ^+ 3dhomejoe.com                 2   6    33    19    -23ms[  -23ms] +&#x2F;-  102ms
  ^- shed.galexander.org           3   6    17    20    -32ms[  -32ms] +&#x2F;-  114ms
  ^- time-a-b.nist.gov             1   6    17    21    +10ms[  +10ms] +&#x2F;-   55ms
</code></pre>
And for comparison<p><pre><code>  pool pool.ntp.org iburst
  pool time.nist.gov iburst

  # chronyc sourcestats 
  Name&#x2F;IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
  ==============================================================================
  time.cloudflare.com         4   3     6  +1363.306  27212.342  +8424us  3911us
  time100.stupi.se            4   4     8  -1051.634  11864.409    -12ms  2419us
  ntp2.flashdance.cx          4   3     7   +183.591  78497.898  -1031us  9048us
  time.cloudflare.com         4   4     7   +566.874  56659.176  +1998us  8584us
  time-e-b.nist.gov           4   3     6     -5.327   7264.481   +710us   988us

  # chronyc sources
  MS Name&#x2F;IP address         Stratum Poll Reach LastRx Last sample
  ===============================================================================
  ^+ time.cloudflare.com           3   6    17    11  -1590us[-2743us] +&#x2F;-   66ms
  ^- time100.stupi.se              1   6    17    10  -5597us[-5597us] +&#x2F;-  116ms
  ^\* ntp2.flashdance.cx            2   6    17    10    -31ms[  -32ms] +&#x2F;-  168ms
  ^- time.cloudflare.com           3   6    17    10    -17ms[  -17ms] +&#x2F;-   98ms
  ^+ time-e-b.nist.gov             1   6    17    11   +504us[ -649us] +&#x2F;-   56ms
</code></pre>
I&#x27;ll stick with a config that queries Stratum 1 time server vs only Stratum 4 servers.<p>\\EDIT: Formatting