Moment Timezone with data just for GMT

moment-timezone-gmt.js

//! moment-timezone.js
//! version : 0.3.0
//! author : Tim Wood
//! license : MIT
//! github.com/moment/moment-timezone

(function (root, factory) {
	"use strict";

	/*global define*/
	if (typeof define === 'function' && define.amd) {
		define(['moment'], factory);                 // AMD
	} else if (typeof exports === 'object') {
		module.exports = factory(require('moment')); // Node
	} else {
		factory(root.moment);                        // Browser
	}
}(this, function (moment) {
	"use strict";

	// Do not load moment-timezone a second time.
	if (moment.tz !== undefined) { return moment; }

	var VERSION = "0.3.0",
		zones = {},
		links = {},

		momentVersion = moment.version.split('.'),
		major = +momentVersion[0],
		minor = +momentVersion[1];

	// Moment.js version check
	if (major < 2 || (major === 2 && minor < 6)) {
		logError('Moment Timezone requires Moment.js >= 2.6.0. You are using Moment.js ' + moment.version + '. See momentjs.com');
	}

	/************************************
		Unpacking
	************************************/

	function charCodeToInt(charCode) {
		if (charCode > 96) {
			return charCode - 87;
		} else if (charCode > 64) {
			return charCode - 29;
		}
		return charCode - 48;
	}

	function unpackBase60(string) {
		var i = 0,
			parts = string.split('.'),
			whole = parts[0],
			fractional = parts[1] || '',
			multiplier = 1,
			num,
			out = 0,
			sign = 1;

		// handle negative numbers
		if (string.charCodeAt(0) === 45) {
			i = 1;
			sign = -1;
		}

		// handle digits before the decimal
		for (i; i < whole.length; i++) {
			num = charCodeToInt(whole.charCodeAt(i));
			out = 60 * out + num;
		}

		// handle digits after the decimal
		for (i = 0; i < fractional.length; i++) {
			multiplier = multiplier / 60;
			num = charCodeToInt(fractional.charCodeAt(i));
			out += num * multiplier;
		}

		return out * sign;
	}

	function arrayToInt (array) {
		for (var i = 0; i < array.length; i++) {
			array[i] = unpackBase60(array[i]);
		}
	}

	function intToUntil (array, length) {
		for (var i = 0; i < length; i++) {
			array[i] = Math.round((array[i - 1] || 0) + (array[i] * 60000)); // minutes to milliseconds
		}

		array[length - 1] = Infinity;
	}

	function mapIndices (source, indices) {
		var out = [], i;

		for (i = 0; i < indices.length; i++) {
			out[i] = source[indices[i]];
		}

		return out;
	}

	function unpack (string) {
		var data = string.split('|'),
			offsets = data[2].split(' '),
			indices = data[3].split(''),
			untils  = data[4].split(' ');

		arrayToInt(offsets);
		arrayToInt(indices);
		arrayToInt(untils);

		intToUntil(untils, indices.length);

		return {
			name    : data[0],
			abbrs   : mapIndices(data[1].split(' '), indices),
			offsets : mapIndices(offsets, indices),
			untils  : untils
		};
	}

	/************************************
		Zone object
	************************************/

	function Zone (packedString) {
		if (packedString) {
			this._set(unpack(packedString));
		}
	}

	Zone.prototype = {
		_set : function (unpacked) {
			this.name    = unpacked.name;
			this.abbrs   = unpacked.abbrs;
			this.untils  = unpacked.untils;
			this.offsets = unpacked.offsets;
		},

		_index : function (timestamp) {
			var target = +timestamp,
				untils = this.untils,
				i;

			for (i = 0; i < untils.length; i++) {
				if (target < untils[i]) {
					return i;
				}
			}
		},

		parse : function (timestamp) {
			var target  = +timestamp,
				offsets = this.offsets,
				untils  = this.untils,
				max     = untils.length - 1,
				offset, offsetNext, offsetPrev, i;

			for (i = 0; i < max; i++) {
				offset     = offsets[i];
				offsetNext = offsets[i + 1];
				offsetPrev = offsets[i ? i - 1 : i];

				if (offset < offsetNext && tz.moveAmbiguousForward) {
					offset = offsetNext;
				} else if (offset > offsetPrev && tz.moveInvalidForward) {
					offset = offsetPrev;
				}

				if (target < untils[i] - (offset * 60000)) {
					return offsets[i];
				}
			}

			return offsets[max];
		},

		abbr : function (mom) {
			return this.abbrs[this._index(mom)];
		},

		offset : function (mom) {
			return this.offsets[this._index(mom)];
		}
	};

	/************************************
		Global Methods
	************************************/

	function normalizeName (name) {
		return (name || '').toLowerCase().replace(/\//g, '_');
	}

	function addZone (packed) {
		var i, zone, zoneName;

		if (typeof packed === "string") {
			packed = [packed];
		}

		for (i = 0; i < packed.length; i++) {
			zone = new Zone(packed[i]);
			zoneName = normalizeName(zone.name);
			zones[zoneName] = zone;
			upgradeLinksToZones(zoneName);
		}
	}

	function getZone (name) {
		return zones[normalizeName(name)] || null;
	}

	function getNames () {
		var i, out = [];

		for (i in zones) {
			if (zones.hasOwnProperty(i) && zones[i]) {
				out.push(zones[i].name);
			}
		}

		return out.sort();
	}

	function addLink (aliases) {
		var i, alias;

		if (typeof aliases === "string") {
			aliases = [aliases];
		}

		for (i = 0; i < aliases.length; i++) {
			alias = aliases[i].split('|');
			pushLink(alias[0], alias[1]);
			pushLink(alias[1], alias[0]);
		}
	}

	function upgradeLinksToZones (zoneName) {
		if (!links[zoneName]) {
			return;
		}

		var i,
			zone = zones[zoneName],
			linkNames = links[zoneName];

		for (i = 0; i < linkNames.length; i++) {
			copyZoneWithName(zone, linkNames[i]);
		}

		links[zoneName] = null;
	}

	function copyZoneWithName (zone, name) {
		var linkZone = zones[normalizeName(name)] = new Zone();
		linkZone._set(zone);
		linkZone.name = name;
	}

	function pushLink (zoneName, linkName) {
		zoneName = normalizeName(zoneName);

		if (zones[zoneName]) {
			copyZoneWithName(zones[zoneName], linkName);
		} else {
			links[zoneName] = links[zoneName] || [];
			links[zoneName].push(linkName);
		}
	}

	function loadData (data) {
		addZone(data.zones);
		addLink(data.links);
		tz.dataVersion = data.version;
	}

	function zoneExists (name) {
		if (!zoneExists.didShowError) {
			zoneExists.didShowError = true;
				logError("moment.tz.zoneExists('" + name + "') has been deprecated in favor of !moment.tz.zone('" + name + "')");
		}
		return !!getZone(name);
	}

	function needsOffset (m) {
		return !!(m._a && (m._tzm === undefined));
	}

	function logError (message) {
		if (typeof console !== 'undefined' && typeof console.error === 'function') {
			console.error(message);
		}
	}

	/************************************
		moment.tz namespace
	************************************/

	function tz (input) {
		var args = Array.prototype.slice.call(arguments, 0, -1),
			name = arguments[arguments.length - 1],
			zone = getZone(name),
			out  = moment.utc.apply(null, args);

		if (zone && !moment.isMoment(input) && needsOffset(out)) {
			out.add(zone.parse(out), 'minutes');
		}

		out.tz(name);

		return out;
	}

	tz.version      = VERSION;
	tz.dataVersion  = '';
	tz._zones       = zones;
	tz._links       = links;
	tz.add          = addZone;
	tz.link         = addLink;
	tz.load         = loadData;
	tz.zone         = getZone;
	tz.zoneExists   = zoneExists; // deprecated in 0.1.0
	tz.names        = getNames;
	tz.Zone         = Zone;
	tz.unpack       = unpack;
	tz.unpackBase60 = unpackBase60;
	tz.needsOffset  = needsOffset;
	tz.moveInvalidForward   = true;
	tz.moveAmbiguousForward = false;

	/************************************
		Interface with Moment.js
	************************************/

	var fn = moment.fn;

	moment.tz = tz;

	moment.defaultZone = null;

	moment.updateOffset = function (mom, keepTime) {
		var offset;
		if (mom._z === undefined) {
			mom._z = moment.defaultZone;
		}
		if (mom._z) {
			offset = mom._z.offset(mom);
			if (Math.abs(offset) < 16) {
				offset = offset / 60;
			}
			if (mom.utcOffset !== undefined) {
				mom.utcOffset(-offset, keepTime);
			} else {
				mom.zone(offset, keepTime);
			}
		}
	};

	fn.tz = function (name) {
		if (name) {
			this._z = getZone(name);
			if (this._z) {
				moment.updateOffset(this);
			} else {
				logError("Moment Timezone has no data for " + name + ". See http://momentjs.com/timezone/docs/#/data-loading/.");
			}
			return this;
		}
		if (this._z) { return this._z.name; }
	};

	function abbrWrap (old) {
		return function () {
			if (this._z) { return this._z.abbr(this); }
			return old.call(this);
		};
	}

	function resetZoneWrap (old) {
		return function () {
			this._z = null;
			return old.apply(this, arguments);
		};
	}

	fn.zoneName = abbrWrap(fn.zoneName);
	fn.zoneAbbr = abbrWrap(fn.zoneAbbr);
	fn.utc      = resetZoneWrap(fn.utc);

	moment.tz.setDefault = function(name) {
		if (major < 2 || (major === 2 && minor < 9)) {
			logError('Moment Timezone setDefault() requires Moment.js >= 2.9.0. You are using Moment.js ' + moment.version + '.');
		}
		moment.defaultZone = name ? getZone(name) : null;
		return moment;
	};

	// Cloning a moment should include the _z property.
	var momentProperties = moment.momentProperties;
	if (Object.prototype.toString.call(momentProperties) === '[object Array]') {
		// moment 2.8.1+
		momentProperties.push('_z');
		momentProperties.push('_a');
	} else if (momentProperties) {
		// moment 2.7.0
		momentProperties._z = null;
	}

	loadData({
		"version": "2014j",
		"zones": [
            "Europe/Belfast|GMT BST BDST|0 -10 -20|0101010101010101010101010101010101010101010101010121212121210101210101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010|-2axa0 Rc0 1fA0 14M0 1fc0 1g00 1co0 1dc0 1co0 1oo0 1400 1dc0 19A0 1io0 1io0 WM0 1o00 14o0 1o00 17c0 1io0 17c0 1fA0 1a00 1lc0 17c0 1io0 17c0 1fA0 1a00 1io0 17c0 1io0 17c0 1fA0 1cM0 1io0 17c0 1fA0 1a00 1io0 17c0 1io0 17c0 1fA0 1a00 1io0 1qM0 Dc0 2Rz0 Dc0 1zc0 Oo0 1zc0 Rc0 1wo0 17c0 1iM0 FA0 xB0 1fA0 1a00 14o0 bb0 LA0 xB0 Rc0 1wo0 11A0 1o00 17c0 1fA0 1a00 1fA0 1cM0 1fA0 1a00 17c0 1fA0 1a00 1io0 17c0 1lc0 17c0 1fA0 1a00 1io0 17c0 1io0 17c0 1fA0 1a00 1a00 1qM0 WM0 1qM0 11A0 1o00 WM0 1qM0 WM0 1qM0 WM0 1qM0 WM0 1tA0 IM0 90o0 U00 1tA0 U00 1tA0 U00 1tA0 U00 1tA0 WM0 1qM0 WM0 1qM0 WM0 1tA0 U00 1tA0 U00 1tA0 11z0 1o00 11A0 1o00 11A0 1o00 11A0 1qM0 11A0 1o00 11A0 1o00 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1o00 11A0 1o00 11A0 1o00 14o0 1o00 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00 11A0 1qM0 WM0 1qM0 WM0 1qM0 WM0 1qM0 11A0 1o00 11A0 1o00"
		],
		"links": [
			"Europe/Belfast|Europe/London"
		]
	});


	return moment;
}));