What is the difference between toGMTstring() and toUTCstring()?

Question

I am saving data in MongoDB server from Node.js application (using Mongoose).

Consider following code:

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var schemaObj = new Schema({
    field1: String,
    field2: String,
    Datefield: Date//So on...
});

mongooseDB = mongoose.createConnection('mongodb://myserver:port/DBname');
mongooseDB.on('error', console.error.bind(console, 'error in connection'));

mongooseDB.once('open', function (err) {
        var objmodel = db.model('myschema', schemaObj); 
        modelObj.field1 ='value1'; 
        modelObj.Datefield = new Date().toGMTString(); //new Date().toUTCString();
        //So on..
        modelObj.save(function (err) {
            if (err)    
                 //Notify err
            else
                //DO some task after save
        });

    });

In the Datefield, Getting following value when I use 'toGMTstring()' or 'toUTCstring()'

 'Thu, 24 Jan 2013 05:49:04 GMT'

I went through the following links:

• toUTCstring()
• toGMTstring()

toGMTString is deprecated and should no longer be used

Could anyone help me in understanding, whats the difference between toUTCstring() and toGMTstring() with respect to Node.js?

Answer 1

GMT and UTC are different timezones, they are Greenwich Mean Time and Coordinated Universal Time respectively. GMT is a 'solar' timezone, whereas UTC is 'atomic'. For most purposes they are essentially the same thing, however UTC is more 'universal'.

Interestingly the documentation you point to for toUTCString still show a GMT output:

var today = new Date();
var UTCstring = today.toUTCString();
// Mon, 03 Jul 2006 21:44:38 GMT

For interchange of data between application I would prefer to use something like ISO8601, which uses the 'Z' suffix for UTC:

2013-01-16T08:19Z

Where the 'Z' confusingly stands for 'Zulu time'!