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NTP Time Check

Query an NTP time server over SNTP and compare its clock with the device clock.

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NTP Time Check

ntp

Input

  • Target: NTP server hostname or IP (for example time.apple.com or pool.ntp.org).
  • Common public servers: time.apple.com, pool.ntp.org, time.google.com, time.cloudflare.com.

Options

  • Samples: number of SNTP queries sent (1, 3, or 5; default 3). The sample with the lowest round-trip delay is used for the offset result.

Output

  • Clock offset in seconds (positive = device clock behind the server) with a plain-language verdict line.
  • Round-trip delay in milliseconds.
  • Server details: stratum, leap indicator, reference ID, NTP version, precision, root delay/dispersion.
  • Server time vs. device time at the moment of the response, plus per-sample offset/delay lines.
  • Kiss-of-Death detection (codes like RATE or DENY) when a server asks the client to stop querying.

Tips

  • Clock drift is a common hidden cause of TLS "certificate not valid" errors and failing one-time passcodes — pair this tool with the TLS Cert Inspector.
  • time.google.com applies leap smearing, so its time can differ slightly from non-smearing servers around a leap second.
  • If no reply arrives, the network may block outbound UDP port 123; try another network or server.

Deeplink

netdebug://ntp?target=pool.ntp.org&samples=5

Tip: in the app, open the Export menu (the share icon) on this screen and choose Copy Deeplink to copy this link as a Universal Link with your current target and options already filled in.