String + Format

If you know the format of an input string, you can use that to parse a date.

TIP

This requires the CustomParseFormat plugin to work

dayjs.extend(customParseFormat);
dayjs('12-25-1995', 'MM-DD-YYYY');

Pass the locale key as the third parameter to parse locale-aware date time string.

require('dayjs/locale/es');
dayjs('2018 Enero 15', 'YYYY MMMM DD', 'es');

You may specify a boolean for the last argument to use strict parsing. Strict parsing requires that the format and input match exactly, including delimiters.

dayjs('1970-00-00', 'YYYY-MM-DD').isValid(); // true
dayjs('1970-00-00', 'YYYY-MM-DD', true).isValid(); // false
dayjs('1970-00-00', 'YYYY-MM-DD', 'es', true).isValid(); // false

If you don't know the exact format of an input string, but know it could be one of many, you can use an array of formats.

dayjs('12-25-2001', ['YYYY', 'YYYY-MM-DD'], 'es', true);

List of all available parsing tokens

Input	Example	Description
YY	01	Two-digit year
YYYY	2001	Four-digit year
M	1-12	Month, beginning at 1
MM	01-12	Month, 2-digits
MMM	Jan-Dec	The abbreviated month name
MMMM	January-December	The full month name
D	1-31	Day of month
DD	01-31	Day of month, 2-digits
H	0-23	Hours
HH	00-23	Hours, 2-digits
h	1-12	Hours, 12-hour clock
hh	01-12	Hours, 12-hour clock, 2-digits
m	0-59	Minutes
mm	00-59	Minutes, 2-digits
s	0-59	Seconds
ss	00-59	Seconds, 2-digits
S	0-9	Hundreds of milliseconds, 1-digit
SS	00-99	Tens of milliseconds, 2-digits
SSS	000-999	Milliseconds, 3-digits
Z	-05:00	Offset from UTC
ZZ	-0500	Compact offset from UTC, 2-digits
A	AM PM	Post or ante meridiem, upper-case
a	am pm	Post or ante meridiem, lower-case
Do	1st... 31st	Day of Month with ordinal
X	1410715640.579	Unix timestamp
x	1410715640579	Unix ms timestamp

Differences to moment

title	parameters	dayjs	moment
invalid date with overflow	('35/22/2010 99:88:77', 'DD-MM-YYYY HH:mm:ss')	'08-11-2011 04:29:17'	'Invalid date'
invalid date with overflow, strict	('35/22/2010 99:88:77', 'DD-MM-YYYY HH:mm:ss', true)	'Invalid Date'	'Invalid date'
'0' day or month (using default values)	('1970-00-00', 'YYYY-MM-DD')	'1970-01-01'	'Invalid date'
'0' day or month (using default values), strict	('1970-00-00', 'YYYY-MM-DD', true)	'Invalid Date'	'Invalid date'
date not matching format	('10/12/2014', 'YYYY-MM-DD')	'01-01-2014'	'12-20-2010'
date not matching format, strict	('10/12/2014', 'YYYY-MM-DD', true)	'Invalid Date'	'Invalid date'
first match vs. longest match	('2012-05-28 10:21:15', ['YYYY', 'YYYY-MM-DD', 'YYYY-MM-DD HH:mm:ss'])	'2012-01-01 00:00:00'	'2012-05-28 10:21:15'
first match vs. longest match, strict	('2012-05-28 10:21:15', ['YYYY', 'YYYY-MM-DD', 'YYYY-MM-DD HH:mm:ss'], true)	'2012-05-28 10:21:15'	'2012-05-28 10:21:15'

List of all recognized separator characters:

-_:.,()/