Hi, I'm using this lib with ESP8266 with the latest core and found that internal clock are 4 seconds faster, than reference. This is not a issue, but ezTime update reports that internal clock i slower, not faster as it is.

14:59:34.144 -> UTC before update: 12:59:38.025
14:59:34.144 -> Querying ntp.ufe.cz ... success (round trip 108 ms)
14:59:34.238 -> Received time: Saturday, 24-Apr-21 12:59:34.279 UTC (internal clock was 3855 ms slow)

Left is time from PC which was synchronized jut before test.
12:59:38.025 is internal time just before update:

Serial.println("UTC before update: " + UTC.dateTime("H:i:s.v")); updateNTP();