ntpc

Tiny NTP client. Works with NTP v3 and v4

Installation

$ bun add ntpc
$ yarn add ntpc
$ npm install ntpc

Usage

import { getTime } from 'ntpc';

const { currentTime } = await getTime('time.apple.com', 123);
console.log(currentTime); // Date(2023-06-08T06:46:08.000Z)

Configuration

import { getTime } from 'ntpc';

const { currentTime } = await getTime('time.apple.com', 123, {
  version: 3, // Customized version (3 | 4)
});
console.log(currentTime); // Date(2023-06-08T06:46:08.000Z)

Response Data

The getTime function returns detailed NTP response data:

import { getTime } from 'ntpc';

const result = await getTime('pool.ntp.org', 123);

console.log(result.currentTime); // Current time from server
console.log(result.data); // Complete NTP packet data

Example Response

{
  currentTime: Date(2023-06-08T06:46:08.237Z),
  data: {
    leapIndicator: 0,               // No leap second warning
    version: 4,                     // NTP version 4
    mode: 4,                        // Server mode
    stratum: 2,                     // Secondary reference
    pollInterval: 6,                // 64 second poll interval (2^6)
    precision: -25,                 // ~30 nanosecond precision (2^-25)
    rootDelay: 26214,               // Round-trip delay to reference
    rootDispersion: 1638,           // Total dispersion
    referenceIdentifier: 134744072, // Reference source IP
    referenceTimestamp: Date(2023-06-08T06:45:32.123Z),
    originTimestamp: Date(1970-01-01T00:00:00.000Z),
    receiveTimestamp: Date(2023-06-08T06:46:08.234Z),
    transmitTimestamp: Date(2023-06-08T06:46:08.237Z)
  }
}

Field Descriptions

• leapIndicator: Warning of impending leap second (0=no warning, 1=+1s, 2=-1s, 3=unsync)
• version: NTP protocol version (3 or 4)
• mode: Association mode (3=client, 4=server, 5=broadcast)
• stratum: Distance from reference clock (1=primary, 2-15=secondary)
• pollInterval: Maximum message interval in log₂ seconds
• precision: System clock precision in log₂ seconds
• rootDelay: Round-trip delay to primary reference source
• rootDispersion: Total dispersion to primary reference
• referenceIdentifier: Reference clock identifier or server IP
• referenceTimestamp: When system clock was last set/corrected
• originTimestamp: Client request departure time (used for delay calculation)
• receiveTimestamp: Server request arrival time
• transmitTimestamp: Server response departure time

License

ntpc is WTFPL licensed.