NTP check

What it does: asks an NTP server for the time (SNTP over UDP/123) and reports how far off this machine's clock is, plus the server's stratum.

Safe to run: yes, read-only — it only asks the time.

Reading results: 'offset' is (server clock − this PC). A large offset means your clock is wrong — fix time sync before chasing TLS-cert, Kerberos/AD-auth, or log-timestamp errors, which all break when the clock drifts. Stratum is the server's distance from a reference clock (1 = best, 16 = unsynchronized).