set-timezone-time

node-time
=========

$3


This module offers simple bindings for the C [time.h][] APIs.
It also offers an extended native Date object with getTimezone()
and setTimezone() functions, which aren't normally part of JavaScript.

Installation
------------

node-time is available through npm:

`` bash
$ npm install time
`


Example
-------

` javascript
var time = require('time');

// Create a new Date instance, representing the current instant in time
var now = new time.Date();

now.setTimezone("America/Los_Angeles");
// .getDate(), .getDay(), .getHours(), etc.
// will return values according to UTC-8

now.setTimezone("America/New_York");
// .getDate(), .getDay(), .getHours(), etc.
// will return values according to UTC-5


// You can also set the timezone during instantiation
var azDate = new time.Date(2010, 0, 1, 'America/Phoenix');
azDate.getTimezone(); // 'America/Phoenix'
`

$3

node-time provides a convenient time.Date object, which is its own Date
constructor independent from your own (or the global) Date object. There are often
times, however, when you would like the benefits of node-time on all Date
instances. To extend the global Date object, simply pass it in as an argument to
the node-time module when requiring:

` js
var time = require('time')(Date);

var d = new Date();
d.setTimezone('UTC');
`


API
---




$3

#### new time.Date()
#### new time.Date(millisecondsFromUTC)
#### new time.Date(dateString [, timezone ])
#### new time.Date(year, month, day [, hour, minute, second, millisecond ] [, timezone ])

A special Date constructor that returns a "super" Date instance, that has
magic _timezone_ capabilities! You can also pass a timezone as the last
argument in order to have a Date instance in the specified timezone.

` javascript
var now = new time.Date();
var another = new time.Date('Aug 9, 1995', 'UTC');
var more = new time.Date(1970, 0, 1, 'Europe/Amsterdam');
`


#### date.setTimezone(timezone [, relative ]) -> Undefined

Sets the timezone for the Date instance. By default this function makes it so
that calls to getHours(), getDays(), getMinutes(), etc. will be relative to
the timezone specified. If you pass true in as the second argument, then
instead of adjusting the local "get" functions to match the specified timezone,
instead the internal state of the Date instance is changed, such that the local
"get" functions retain their values from before the setTimezone call.

` javascript
date.setTimezone("America/Argentina/San_Juan")

// Default behavior:
a = new time.Date()
a.toString()
// 'Wed Aug 31 2011 09:45:31 GMT-0700 (PDT)'
a.setTimezone('UTC')
a.toString()
// 'Wed Aug 31 2011 16:45:31 GMT+0000 (UTC)'

// Relative behavior:
b = new time.Date()
b.toString()
// 'Wed Aug 31 2011 10:48:03 GMT-0700 (PDT)'
b.setTimezone('UTC', true)
b.toString()
// 'Wed Aug 31 2011 10:48:03 GMT+0000 (UTC)'
`


#### date.getTimezone() -> String

Returns a String containing the currently configured timezone for the date instance.
This must be called _after_ setTimezone() has been called.

` javascript
date.getTimezone();
// "America/Argentina/San_Juan"
`


#### date.getTimezoneAbbr() -> String

Returns the abbreviated timezone name, also taking daylight savings into consideration.
Useful for the presentation layer of a Date instance.

` javascript
date.getTimezoneAbbr();
// "ART"
`




$3

Same as the native JavaScript Date.parse() function, only this version allows
for a second, optional, timezone argument, which specifies the timezone in
which the date string parsing will be resolved against. This function is also
aliased as time.parse().

` javascript
time.Date.parse("1970, January 1"); // <- Local Time
// 28800000
time.Date.parse("1970, January 1", "Europe/Copenhagen");
// -3600000
time.Date.parse("1970, January 1", "UTC");
// 0
`




$3

Transforms a "regular" Date instance into one of node-time's "extended" Date instances.

` javascript
var d = new Date();
// d.setTimezone() does not exist...
time.extend(d);
d.setTimezone("UTC");
`




$3

Binding for time(). Returns the number of seconds since Jan 1, 1900 UTC.
These two are equivalent:

` javascript
time.time();
// 1299827226
Math.floor(Date.now() / 1000);
// 1299827226
`




$3

Binding for tzset(). Sets up the timezone information that localtime() will
use based on the specified _timezone_ variable, or the current process.env.TZ
value if none is specified. Returns an Object containing information about the
newly set timezone, or throws an Error if no timezone information could be loaded
for the specified timezone.

` javascript
time.tzset('US/Pacific');
// { tzname: [ 'PST', 'PDT' ],
// timezone: 28800,
// daylight: 1 }
`




$3

Binding for localtime(). Accepts a Number with the number of seconds since the
Epoch (i.e. the result of time()), and returns a "broken-down" Object
representation of the timestamp, according the the currently configured timezone
(see tzset()).

` javascript
time.localtime(Date.now()/1000);
// { seconds: 38,
// minutes: 7,
// hours: 23,
// dayOfMonth: 10,
// month: 2,
// year: 111,
// dayOfWeek: 4,
// dayOfYear: 68,
// isDaylightSavings: false,
// gmtOffset: -28800,
// timezone: 'PST' }
`




$3

The currentTimezone property always contains a String to the current timezone
being used by node-time. This property is reset every time the tzset()
function is called. Individual time.Date` instances may have independent
timezone settings than what this one is...

[Node]: http://nodejs.org
[time.h]: http://en.wikipedia.org/wiki/Time.h