useful-date

useful date parsing and formatting library.

useful-date extends the Date and Date.prototype using Object.defineProperty — it will not create new enumerable methods and properties and it will not over-write any existing methods.

Installation

Install with component(1):

$ component install muigui/useful-date

Install with npm:

$ npm install useful-date

API

Static methods

localize( locale:String ):Date

sets the underlying locale.

Example:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );
	require( 'useful-date/locale/en-US.js' );

    Date.localize( 'en-US' );

    Date.formats.short_date // returns => 'm/d/Y'

    Date.localize( 'en-GB' );

    Date.formats.short_date // returns => 'd/m/Y'

isLeapYear( year:String ):Boolean

Returns true if the passed 4 digit year is a leap year.

NOTE: This method is located in the locale file. If your calendar system does not contain leap years, you can simply change the method to only return false.

getOrdinal( date:Number ):String

Returns the ordinal for a given date.

Example:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

     Date.getOrdinal( 1 );  // returns => "st"
     Date.getOrdinal( 10 ); // returns => "th"
     Date.getOrdinal( 22 ); // returns => "nd"
     Date.getOrdinal( 33 ); // returns => "rd"

NOTE: Ordinals and the getOrdinal This method is located in the locale file. You can simply change the ordinal Array to your specific language; overwrite the getOrdinal method or both.

setLeapYear( date:Date ):Void

Sets the inlcuded locale's February day count to the correct number of days, based on whether or not the date is a leap year or not.

NOTE: This method is located in the locale file. If your calendar system does not contain leap years, you can simply change the method to do nothing.

coerce( date:String, format:String ):Date

Takes a date String and a format String based on the Date formatting and parsing options described below and returns a – hopefully – correct and valid Date.

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

    Date.coerce( 'Sunday, the 1st of January 2012', 'l, <the> jS <of> F Y' ); // returns => Date { Sun Jan 01 2012 00:00:00 GMT+0000 (GMT) }
    Date.coerce( '2012-01-01T00:00:00+00:00',        Date.formats.ISO_8601 ); // returns => Date { Sun Jan 01 2012 00:00:00 GMT+0000 (GMT) }

Static properties

filters

An Object of all the available filters for formatting a Date.

IMPORTANT: Don't change these unless you know what you are doing!

formats

An Object containing some default date formats:

ISO_8601	Y-m-dH:i:sP
ISO_8601_SHORT	Y-m-d
RFC_850	l, d-M-y H:i:s T
RFC_2822	D, d M Y H:i:s O
sortable	Y-m-d H:i:sO

Instance methods

adjust( interval:Object|String[, value:Number] ):Date

Your one stop shop for all Date arithmetic. Adjusts the Date based on the passed interval, by the passed numeric value.

Note: The method also accepts a single Object param where each key is the interval and each value is the number to adjust the Date by.

Valid intervals are: year, month, week, day, hr, min, sec, ms.

Example:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

    var date = new Date( 2012, 0, 1 ); // Date {Sun Jan 01 2012 00:00:00 GMT+0000 (GMT)}

    date.adjust( Date.DAY,   1 );      // Date {Mon Jan 02 2012 00:00:00 GMT+0000 (GMT)}
    date.adjust( Date.HOUR, -1 );      // Date {Sun Jan 01 2012 23:00:00 GMT+0000 (GMT)}
    date.adjust( {
       year : -1, month : -1, day : 24,
       hr   :  1, sec   : -1
    } );                               // Date {Sat Dec 25 2010 23:59:59 GMT+0000 (GMT)}

between( date_lower:Date, date_higher:Date ):Boolean

Checks to see if the Date instance is in between the two passed Dates.

Example:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

    var date = new Date( 2012, 0, 1 );

    date.between( new Date( 2011, 0, 1 ), new Date( 2013, 0, 1 ) ); // returns => true;

    date.between( new Date( 2013, 0, 1 ), new Date( 2011, 0, 1 ) ); // returns => false;

clearTime():Date

Clears the time from the Date instance.

clone():Date

Returns a clone of the current Date.

diff( [date:Date, exclude:String] ):Object

Returns an Object describing the difference between the Date instance and now — or the optionally passed Date.

The Object will contain any or all of the following properties:

Prop	Type	Description
tense	Number	This will either be: -1 The Date instance is less than now or the passed Date, i.e. in the past 0 The Date instance is equal to now or the passed Date, i.e. in the present. NOTE: If tense is 0 then the Object will most probably have no other properties, except value, which will be zero. 1 The Date instance is greater than now or the passed Date, i.e. in the future NOTE: To make the diff Object's values easier to work with all other properties will be positive Numbers. You should use the tense property as your reference for the diff being in the past, present or future.
value	Number	The — absolute — number of milliseconds difference between the two Dates.
years	Number	The number of years the Date instance is ahead or behind the passed Date.
months	Number	The months of years the Date instance is ahead or behind the passed Date.
weeks	Number	The weeks of years the Date instance is ahead or behind the passed Date.
days	Number	The days of years the Date instance is ahead or behind the passed Date.
hours	Number	The hours of years the Date instance is ahead or behind the passed Date.
minutes	Number	The minutes of years the Date instance is ahead or behind the passed Date.
seconds	Number	The seconds of years the Date instance is ahead or behind the passed Date.
milliseconds	Number	The number of milliseconds the Date instance is ahead or behind the passed Date or now.

NOTE: If any property — other than tense & value — is zero it will be omitted from the diff Object.

Example:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

     ( new Date( 2012, 0, 1 ) ).diff( new Date( 2012, 0, 1 ) )             // returns => { tense :  0 }

     ( new Date( 2012, 0, 1 ) ).diff( new Date( 2012, 0, 2 ) )             // returns => { tense : -1, value : 86400000,    days  : 1 }

     ( new Date( 2012, 0, 2 ) ).diff( new Date( 2012, 0, 1 ) )             // returns => { tense :  1, value : 86400000,    days  : 1 }

     ( new Date( 2012, 0, 1 ) ).diff( new Date( 2010, 9, 8, 7, 6, 5, 4 ) ) // returns => { tense :  1, value : 38858034996, years : 1, months : 2, weeks : 3, days : 3, hours : 17, minutes : 53, seconds : 54, ms : 995 }

NOTE: You can supply a space delimited String defining which properties you want to exclude from the result and diff will either pass the current calculation to the next time unit or, if there are none will round off — up if over .5 or down if less, uses Math.round to figure this out — to the previous time unit.

Exclusion codes:

• - will exclude the time unit from the diff Object.
• + will include the time unit in the diff Object. Note: this is the same as not including the time unit in the exclusions String.
• > will exclude all time units from this time unit down from the diff Object.

Example with exclusions:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

     ( new Date( 2012, 0, 1 ) ).diff( new Date( 2012, 0, 2 ), '-days' )                              // returns => { tense : -1, value : 86400000,    hours  : 24 }

     ( new Date( 2012, 0, 2 ) ).diff( new Date( 2012, 0, 1 ), '-days' )                              // returns => { tense :  1, value : 86400000,    hours  : 24 }

     ( new Date( 2012, 0, 1 ) ).diff( new Date( 2010, 9, 8, 7, 6, 5, 4 ), '-years -weeks >minutes' ) // returns => { tense :  1, value : 38858034996, months : 14, days : 29, hours : 18 }

format( format:String ):String

Returns a string representation of the Date instance, based on the passed format. See the Date formatting and parsing options below.

Example:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

    ( new Date( 2012, 0, 1 ) ).format( 'c' );                   // returns => "2012-01-01T00:00:00.000Z"
 // which is a short hand format for:
    ( new Date( 2012, 0, 1 ) ).format( 'Y-m-d<T>H:i:s.u<Z>' );  // returns => "2012-01-01T00:00:00.000Z"

    ( new Date( 2012, 0, 1 ) ).format( 'l, <the> nS <of> F Y' ) // returns => "Sunday, the 1st of January 2012"

You can use predefined formats found in Date.formats. Hint: You can do:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

    console.dir( Date.formats );

within your browser's JavaScript console to see a list of available formats.

Previously used formats are also cached to save the overhead of having to create a new Function everytime you want to format a date.

getDayOfYear():Number

Returns the zero based day of the year.

getFirstOfTheMonth():Date

Returns a Date instance of the first day of this Date instance's month.

getGMTOffset( [colon:Boolean] ):String

Returns the Date instances offset from GMT.

getISODay():Number

Returns the ISO day of the week.

getISODaysInYear():Number

Returns the ISO number of days in the year.

getISOFirstMondayOfYear():Date

Returns the ISO first Monday of the year.

getISOWeek():Number

Returns the ISO week of the year

getISOWeeksInYear():Number

Returns the number of weeks in the ISO year.

getLastOfTheMonth():Date

Returns a Date instance of the last day of this Date instance's month.

getWeek():Number

Returns the week of the year, based on the dayOfYear divided by 7.

Example:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

    ( new Date( 2012, 0, 1 ) ).getWeek();   // returns => 0
    ( new Date( 2012, 2, 13 ) ).getWeek();  // returns => 10
    ( new Date( 2012, 11, 31 ) ).getWeek(); // returns => 52

isDST():Boolean

Returns true if the Date instance is within daylight savings time.

isLeapYear():Boolean

Returns true if the Date instance is a leap year.

lexicalize( [now:Date, format:String] ):String

Returns a String representation of the difference between the date instance and now, or the passed Date.

Available formats

The default format is approx, however this can be over-written by changing the locale file and/ or by passing in the desired format to the method.

approx	Will return an approximate difference. e.g. about 2 days ago; almost 1 and a half years from now.
exact	Will return the exact difference, e.g. 2 days 3 hours and 5 minutes ago; 1 year, 4 months, 2 weeks, 1 day, 5 hours, 3 minutes and 7 seconds from now.

Example:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

	var date = new Date( 2012, 0, 1 );

	date.clone().adjust( { hr : -3, day : -2 } ).lexicalize( date, 'approx' ); // returns => "just over 2 days ago"
	date.clone().adjust( { hr : -3, day : -2 } ).lexicalize( date, 'exact' );  // returns => "2 days and 3 hours ago"

	date.lexicalize( date.clone().adjust( { hr : -6, day : -2 } ), 'approx' ); // returns => "almost 2 and a half days from now"
	date.lexicalize( date.clone().adjust( { hr : -6, day : -2 } ), 'exact' );  // returns => "2 days and 6 hours from now"

setWeek():Number(UnixTimeStamp)

Sets the week of the year from the 1st January.

Example:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

    new Date( ( new Date( 2012, 0, 1 ) ).setWeek( 17 ) ); // returns => Date {Sun Apr 29 2012 00:00:00 GMT+0100 (BST)}

    ( new Date( 2012, 2, 13 ) ).setWeek( 17 );            // returns => 1335654000000 same as above

    ( new Date( 2012, 11, 31 ) ).setWeek( 17 );           // returns => 1335654000000

timezone():String

Returns the JavaScript engine's Date.prototype.toString() timezone abbreviation.

Date formatting and parsing options

escaping characters

If you want to escape characters that are used by the Date parser you can wrap them between <>.

Example:

	require( 'useful-date' );
	require( 'useful-date/locale/en-GB.js' );

    ( new Date( 2012, 0, 1 ) ).format( 'l, <the> jS <of> F Y' ); // returns => "Sunday, the 1st of January 2012"

day

d	Day of the month, 2 digits with leading zeros
D	A textual representation of a day, three letters
j	Day of the month without leading zeros
l	A full textual representation of the day of the week
N	ISO-8601 numeric representation of the day of the week
S	English ordinal suffix for the day of the month, 2 characters
w	Numeric representation of the day of the week
z	The day of the year (starting from 0)

### week

W	ISO-8601 week number of year, weeks starting on Monday

### month

F	A full textual representation of a month
m	Numeric representation of a month, with leading zeros
M	A short textual representation of a month, three letters
n	Numeric representation of a month, without leading zeros
t	Number of days in the given month

### year

L	Whether it's a leap year
o	ISO-8601 year number. This has the same value as Y, except that if the ISO week number (W) belongs to the previous or next year, that year is used instead.
Y	A full numeric representation of a year, 4 digits
y	A two digit representation of a year

### time

a	Lowercase Ante meridiem and Post meridiem
A	Uppercase Ante meridiem and Post meridiem
g	12-hour format of an hour without leading zeros
G	24-hour format of an hour without leading zeros
h	12-hour format of an hour with leading zeros
H	24-hour format of an hour with leading zeros
i	Minutes with leading zeros
s	Seconds, with leading zeros
u	Milliseconds

### timezone

O	Difference to Greenwich time (GMT) in hours
P	Difference to Greenwich time (GMT) with colon between hours and minutes
T	Timezone abbreviation
Z	Timezone offset in seconds. The offset for timezones west of UTC is always negative, and for those east of UTC is always positive.

### full date/time

c	ISO 8601 date
r	RFC 2822 formatted date
U	Seconds since the Unix Epoch January 1 1970 00:00:00 GMT

### custom

e	this is a convenience for `date.lexicalize( 'exact' );`
x	this is a convenience for `date.lexicalize( 'approx' );`

License

(The MIT License)

Copyright (c) 2011 christos "constantology" constandinou http://muigui.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.