var Sntp = require('sntp');

// All options are optional

var options = {
    host: 'nist1-sj.ustiming.org',  // Defaults to pool.ntp.org
    port: 123,                      // Defaults to 123 (NTP)
    resolveReference: true,         // Default to false (not resolving)
    timeout: 1000                   // Defaults to zero (no timeout)
};

// Request server time

Sntp.time(options, function (err, time) {

    if (err) {
        console.log('Failed: ' + err.message);
        process.exit(1);
    }

    console.log('Local clock is off by: ' + time.t + ' milliseconds');
    process.exit(0);
});

// Request offset once

Sntp.offset(function (err, offset) {

    console.log(offset);                    // New (served fresh)

    // Request offset again

    Sntp.offset(function (err, offset) {

        console.log(offset);                // Identical (served from cache)
    });
});

var before = Sntp.now();                    // System time without offset

Sntp.start(function () {

    var now = Sntp.now();                   // With offset
    Sntp.stop();
});