Quick check getting responses from ntp servers and see the deviation between them
timeoutInMillis=1000 g1=time.google.com l1=10.10.0.1 l2=192.168.0.1 l3=192.168.0.14 l4=192.168.0.63 l5=10.10.2.197 c1=time.cloudflare.com f1=time.facebook.com w1=time.windows.com a1=time.apple.com n1=time-a-g.nist.gov np=pool.ntp.org op=opnsense.pool.ntp.org ap=amazon.pool.ntp.org pp=pfsense.pool.ntp.org mil1=tick.usno.navy.mil
08:50:01.590 [main] ERROR SntpTest - opnsense.pool:opnsense.pool.ntp.org:[---- SNTP request failed for opnsense.pool.ntp.org]
08:50:01.603 [main] ERROR SntpTest - amazon.pool:amazon.pool.ntp.org:[---- SNTP request failed for amazon.pool.ntp.org]
08:50:02.603 [main] ERROR SntpTest - DNS2:192.168.0.14:[---- SNTP request failed for 192.168.0.14]
08:50:03.653 [main] ERROR SntpTest - CentosLan2:192.168.2.197:[---- SNTP request failed for 192.168.2.197]
08:50:03.694 [main] ERROR SntpTest - pfsense.pool:pfsense.pool.ntp.org:[---- SNTP request failed for pfsense.pool.ntp.org]
08:50:03.775 [main] ERROR SntpTest - OPNsense:192.168.0.1:[Invalid response from NTP server. Root delay violation 132.4920654296875]
08:50:04.109 [main] ERROR SntpTest - ntp.pool:pool.ntp.org:[Server response delay too large for comfort 210]
08:50:05.148 [main] ERROR SntpTest - Homeseer:10.10.1.45:[---- SNTP request failed for 10.10.1.45]
08:50:06.148 [main] ERROR SntpTest - Iris5:10.10.2.45:[---- SNTP request failed for 10.10.2.45]
08:50:06.150 [main] ERROR SntpTest - Iris6:10.10.2.48:[Invalid response from NTP server. Root delay violation 132.99560546875, Invalid response from NTP server. Root dispersion violation 2752.62451171875]
08:50:07.151 [main] ERROR SntpTest - Iris3:10.10.2.46:[---- SNTP request failed for 10.10.2.46]
08:50:08.164 [main] ERROR SntpTest - Iris4:10.10.2.47:[---- SNTP request failed for 10.10.2.47]
08:50:09.166 [main] ERROR SntpTest - CentosLan10:10.10.2.197:[---- SNTP request failed for 10.10.2.197]
08:50:09.166 [main] WARN SntpTest - ---------------------------------------
08:50:09.166 [main] WARN SntpTest - Average offset from 8 good responders:-83 millisecs
08:50:09.175 [main] WARN SntpTest - name: host: offset: Deviation
08:50:09.176 [main] WARN SntpTest - navy: tick.usno.navy.mil: -79: 4
08:50:09.176 [main] WARN SntpTest - DNS1: 192.168.0.63: -84: -1
08:50:09.176 [main] WARN SntpTest - google: time.google.com: -87: -4
08:50:09.184 [main] WARN SntpTest - cloudflare: time.cloudflare.com: -85: -2
08:50:09.184 [main] WARN SntpTest - windows: time.windows.com: -85: -2
08:50:09.184 [main] WARN SntpTest - nist: time-a-g.nist.gov: -83: 0
08:50:09.185 [main] WARN SntpTest - apple: time.apple.com: -78: 5
08:50:09.194 [main] WARN SntpTest - gateway: 10.10.0.1: -85: -2
note 192.168.0.1 and 10.10.2.48 turned out the be the most reliable ones for my cameras to use depite errors seen here from a Windows PC.
See https://securitycam101.rmrr42.com/2020/09/syncing-time.html