15 KiB
date-and-time
This library is just a function collection for manipulating JS date and time. It's tiny, simple, easy to learn.
Why
Because JS modules nowadays are getting more huge and complex, and there are also many dependencies. Trying to keep each module simple and small is meaningful.
Features
- Minimalist. Less than 2k. (minified and gzipped)
- Universal / Isomorphic. Wherever JS runtime works.
- Multi language support.
- Not extending built-in Date object.
- Older browser support. Even works on IE6. :)
Install
- via npm:
$ npm install date-and-time --save
- using directly:
<script src="/path/to/date-and-time.min.js"></script>
Recent Changes
-
0.9.0 (Locale Update)
- Renewal of the locale system. Some functions were merged (Breaking Change).
- Added a plugin system. You could extend the formatter and the parser by using it.
- The
format()
has come to support a user original token in association with the plugin system.
-
0.8.0 (Parser Update)
- The
parse()
has come to returnInvalid Date
instead ofNaN
when parsing is failure (Breaking Change). - Added
preparse()
. It returns a Date Structure. - The
isValid()
has come to take a Date Structure in addition to a date string. - The
isLeapYear()
has come to take a year (number type) instead of a Date object (Breaking Change).
- The
Usage
- Node.js:
const date = require('date-and-time');
- ES6 transpiler:
import date from 'date-and-time';
- Browser:
window.date; // global object
API
format(dateObj, formatString[, utc])
Formatting a date
- @param {Date} dateObj - a Date object
- @param {string} formatString - a format string
- @param {boolean} [utc] - output as UTC
- @returns {string} a formatted string
const now = new Date();
date.format(now, 'YYYY/MM/DD HH:mm:ss'); // => '2015/01/02 23:14:05'
date.format(now, 'ddd., MMM. DD YYYY'); // => 'Fri., Jan. 02 2015'
date.format(now, 'hh:mm A [GMT]Z'); // => '11:14 p.m. GMT-0800'
date.format(now, 'hh:mm A [GMT]Z', true); // => '07:14 a.m. GMT+0000'
Available tokens and their meanings are as follows:
token | meaning | example |
---|---|---|
YYYY | year | 0999, 2015 |
YY | year | 15, 99 |
Y | year | 999, 2015 |
MMMM | month | January, December |
MMM | month | Jan, Dec |
MM | month | 01, 12 |
M | month | 1, 12 |
DD | day | 02, 31 |
D | day | 2, 31 |
dddd | day of week | Friday, Sunday |
ddd | day of week | Fri, Sun |
dd | day of week | Fr, Su |
HH | 24-hour | 23, 08 |
H | 24-hour | 23, 8 |
A | meridiem | a.m., p.m. |
hh | 12-hour | 11, 08 |
h | 12-hour | 11, 8 |
mm | minute | 14, 07 |
m | minute | 14, 7 |
ss | second | 05, 10 |
s | second | 5, 10 |
SSS | millisecond | 753, 022 |
SS | millisecond | 75, 02 |
S | millisecond | 7, 0 |
Z | timezone | +0100, -0800 |
NOTE 1. Comments
Strings in parenthese [...]
in the formatString
will be ignored as comments:
date.format(new Date(), 'DD-[MM]-YYYY'); // => '02-MM-2015'
date.format(new Date(), '[DD-[MM]-YYYY]'); // => 'DD-[MM]-YYYY'
NOTE 2. UTC
This function usually outputs a local date-time string. Set to true a utc
option (the 3rd parameter) if you would like to get a UTC date/time string.
date.format(new Date(), 'hh:mm A [GMT]Z'); // => '11:14 p.m. GMT-0800'
date.format(new Date(), 'hh:mm A [GMT]Z', true); // => '07:14 a.m. GMT+0000'
NOTE 3. More Tokens
You could also define your own tokens. See PLUGINS.md for details.
parse(dateString, formatString[, utc])
Parsing a date string
- @param {string} dateString - a date string
- @param {string} formatString - a format string
- @param {boolean} [utc] - input as UTC
- @returns {Date} a constructed date
date.parse('2015/01/02 23:14:05', 'YYYY/MM/DD HH:mm:ss'); // => Jan. 2 2015 23:14:05 GMT-0800
date.parse('02-01-2015', 'DD-MM-YYYY'); // => Jan. 2 2015 00:00:00 GMT-0800
date.parse('11:14:05 p.m.', 'hh:mm:ss A'); // => Jan. 1 1970 23:14:05 GMT-0800
date.parse('11:14:05 p.m.', 'hh:mm:ss A', true); // => Jan. 1 1970 15:14:05 GMT-0800
date.parse('Jam. 1 2017', 'MMM. D YYYY'); // => Invalid Date
date.parse('Feb. 29 2016', 'MMM. D YYYY'); // => Feb. 29 2016 00:00:00 GMT-0800
date.parse('Feb. 29 2017', 'MMM. D YYYY'); // => Invalid Date
Available tokens and their meanings are as follows:
token | meaning | example |
---|---|---|
YYYY | year | 2015, 1999 |
YY | year | 15, 99 |
MMMM | month | January, December |
MMM | month | Jan, Dec |
MM | month | 01, 12 |
M | month | 1, 12 |
DD | day | 02, 31 |
D | day | 2, 31 |
HH | 24-hour | 23, 08 |
H | 24-hour | 23, 8 |
hh | 12-hour | 11, 08 |
h | 12-hour | 11, 8 |
A | meridiem | a.m., p.m. |
mm | minute | 14, 07 |
m | minute | 14, 7 |
ss | second | 05, 10 |
s | second | 5, 10 |
SSS | millisecond | 753, 022 |
SS | millisecond | 75, 02 |
S | millisecond | 7, 0 |
NOTE 1. Invalid Date
If the function fails to parse, it will return Invalid Date
. Notice that the Invalid Date
is a Date object, not NaN
or null
. You could tell whether the Date object is invalid as follows:
const today = date.parse('Jam. 1 2017', 'MMM. D YYYY');
if (isNaN(today)) {
// Failure
}
NOTE 2. UTC
This function usually assumes the dateString
is local date-time. Set to true a utc
option (the 3rd parameter) if it is UTC.
date.parse('11:14:05 p.m.', 'hh:mm:ss A'); // => Jan. 1 1970 23:14:05 GMT-0800
date.parse('11:14:05 p.m.', 'hh:mm:ss A', true); // => Jan. 1 1970 15:14:05 GMT-0800
NOTE 3. Default Date Time
Default date is January 1, 1970
, time is 00:00:00.000
. Values not passed will be complemented with them:
date.parse('11:14:05 p.m.', 'hh:mm:ss A'); // => Jan. 1 1970 23:14:05 GMT-0800
date.parse('Feb. 2000', 'MMM. YYYY'); // => Feb. 1 2000 00:00:00 GMT-0800
NOTE 4. Max Date / Min Date
Parsable maximum date is December 31, 9999
, minimum date is January 1, 0001
.
date.parse('Dec. 31 9999', 'MMM. D YYYY'); // => Dec. 31 9999 00:00:00 GMT-0800
date.parse('Dec. 31 10000', 'MMM. D YYYY'); // => Invalid Date
date.parse('Jan. 1 0001', 'MMM. D YYYY'); // => Jan. 1 0001 00:00:00 GMT-0800
date.parse('Jan. 1 0000', 'MMM. D YYYY'); // => Invalid Date
NOTE 5. Auto Mapping
The YY
token maps the year 69 or less to the 2000s, the year 70 or more to the 1900s. Using it is not recommended.
date.parse('Dec. 31 0', 'MMM. D YY'); // => Dec. 31 2000 00:00:00 GMT-0800
date.parse('Dec. 31 69', 'MMM. D YY'); // => Dec. 31 2069 00:00:00 GMT-0800
date.parse('Dec. 31 70', 'MMM. D YY'); // => Dec. 31 1970 00:00:00 GMT-0800
date.parse('Dec. 31 99', 'MMM. D YY'); // => Dec. 31 1999 00:00:00 GMT-0800
NOTE 6. 12-hour notation and Meridiem
If use the hh
or h
(12-hour) token, use together the A
(meridiem) token to get the right value.
date.parse('11:14:05', 'hh:mm:ss'); // => Jan. 1 1970 11:14:05 GMT-0800
date.parse('11:14:05 p.m.', 'hh:mm:ss A'); // => Jan. 1 1970 23:14:05 GMT-0800
NOTE 7. Comments
Strings in parenthese [...]
in the formatString will be ignored as comments:
date.parse('12 hours 34 minutes', 'HH hours mm minutes'); // => Invalid Date
date.parse('12 hours 34 minutes', 'HH [hours] mm [minutes]'); // => Jan. 1 1970 12:34:00 GMT-0800
As a white space works as a wild card, you could also write as follows:
date.parse('12 hours 34 minutes', 'HH mm '); // => Jan. 1 1970 12:34:00 GMT-0800
preparse(dateString, formatString)
Pre-parsing a date string
- @param {string} dateString - a date string
- @param {string} formatString - a format string
- @returns {Object} a date structure
This function takes exactly the same parameters with the parse()
, but returns a date structure as follows unlike it:
date.preparse('2015/01/02 23:14:05', 'YYYY/MM/DD HH:mm:ss');
{
Y: 2015, // Year
M: 1, // Month
D: 2, // Day
H: 23, // 24-hour
A: 0, // Meridiem
h: 0, // 12-hour
m: 14, // Minute
s: 5, // Second
S: 0, // Millisecond
_index: 19, // Pointer offset
_length: 19, // Length of the date string
_match: 6 // Token matching count
}
This object shows a parsing result. You will be able to tell from it how the date string was parsed(, or why the parsing was failed).
isValid(arg[, formatString])
Validation
- @param {Object|string} arg - a date structure or a date string
- @param {string} [formatString] - a format string
- @returns {boolean} whether the date string is a valid date
This function takes either exactly the same parameters with the parse()
or a date structure which the preparse()
returns, evaluates the validity of them.
date.isValid('2015/01/02 23:14:05', 'YYYY/MM/DD HH:mm:ss'); // => true
date.isValid('29-02-2015', 'DD-MM-YYYY'); // => false
const result = date.preparse('2015/01/02 23:14:05', 'YYYY/MM/DD HH:mm:ss');
date.isValid(result); // => true
addYears(dateObj, years)
Adding years
- @param {Date} dateObj - a Date object
- @param {number} years - number of years to add
- @returns {Date} a date after adding the value
const now = new Date();
const next_year = date.addYears(now, 1);
addMonths(dateObj, months)
Adding months
- @param {Date} dateObj - a Date object
- @param {number} months - number of months to add
- @returns {Date} a date after adding the value
const now = new Date();
const next_month = date.addMonths(now, 1);
addDays(dateObj, days)
Adding days
- @param {Date} dateObj - a Date object
- @param {number} days - number of days to add
- @returns {Date} a date after adding the value
const now = new Date();
const yesterday = date.addDays(now, -1);
addHours(dateObj, hours)
Adding hours
- @param {Date} dateObj - a Date object
- @param {number} hours - number of hours to add
- @returns {Date} a date after adding the value
const now = new Date();
const an_hour_ago = date.addHours(now, -1);
addMinutes(dateObj, minutes)
Adding minutes
- @param {Date} dateObj - a Date object
- @param {number} minutes - number of minutes to add
- @returns {Date} a date after adding the value
const now = new Date();
const two_minutes_later = date.addMinutes(now, 2);
addSeconds(dateObj, seconds)
Adding seconds
- @param {Date} dateObj - a Date object
- @param {number} seconds - number of seconds to add
- @returns {Date} a date after adding the value
const now = new Date();
const three_seconds_ago = date.addSeconds(now, -3);
addMilliseconds(dateObj, milliseconds)
Adding milliseconds
- @param {Date} dateObj - a Date object
- @param {number} milliseconds - number of milliseconds to add
- @returns {Date} a date after adding the value
const now = new Date();
const a_millisecond_later = date.addMilliseconds(now, 1);
subtract(date1, date2)
Subtracting
- @param {Date} date1 - a Date object
- @param {Date} date2 - a Date object
- @returns {Object} a result object subtracting date2 from date1
const today = new Date(2015, 0, 2);
const yesterday = new Date(2015, 0, 1);
date.subtract(today, yesterday).toDays(); // => 1 = today - yesterday
date.subtract(today, yesterday).toHours(); // => 24
date.subtract(today, yesterday).toMinutes(); // => 1440
date.subtract(today, yesterday).toSeconds(); // => 86400
date.subtract(today, yesterday).toMilliseconds(); // => 86400000
isLeapYear(y)
Leap year
- @param {number} y - year
- @returns {boolean} whether the year is a leap year
const date1 = new Date(2015, 0, 2);
const date2 = new Date(2012, 0, 2);
date.isLeapYear(date1); // => false
date.isLeapYear(date2); // => true
isSameDay(date1, date2)
Comparison of two dates
- @param {Date} date1 - a Date object
- @param {Date} date2 - a Date object
- @returns {boolean} whether the dates are the same day (times are ignored)
const date1 = new Date(2017, 0, 2, 0); // Jan. 2 2017 00:00:00
const date2 = new Date(2017, 0, 2, 23, 59); // Jan. 2 2017 23:59:00
const date3 = new Date(2017, 0, 1, 23, 59); // Jan. 1 2017 23:59:00
date.isSameDay(date1, date2); // => true
date.isSameDay(date1, date3); // => false
locale([code[, locale]])
Change locale or setting a new locale definition
- @param {string} [code] - language code
- @param {Object} [locale] - locale definition
- @returns {string} current language code
Returns current language code if called without any parameters.
date.locale(); // "en"
To switch to any other language, call it with a language code.
date.locale('es'); // Switch to Spanish
To define a new locale, call it with new language code and a locale definition. See LOCALE.md for details.
extend(extension)
Locale extension
- @param {Object} extension - locale definition
- @returns {void}
Extends a current locale (formatter and parser). See PLUGINS.md for details.
plugin(name[, extension])
Plugin import or definition
- @param {string} name - plugin name
- @param {Object} [extension] - locale definition
- @returns {void}
Plugin is a named locale definition defined with the extend()
. See PLUGINS.md for details.
Browser Support
Chrome, Firefox, Safari, Edge, and Internet Explorer 6+.
License
MIT