I have a date in this format: dd.mm.yyyy
When I instantiate a JavaScript date with it, it gives me a NaN
In c# I can specify a date format, to say: here you have my string, it's in this format, please make a Datetime of it.
Is this possible in JavaScript too? If not, is there an easy way?
I would prefer not to use a substring for day, substring for month etc. because my method must also be capable of german, italian, english etc. dates.
You will need to create a function to extract the date parts and use them with the Date constructor.
Note that this constructor treats months as zero based numbers (0=Jan, 1=Feb, ..., 11=Dec).
For example:
function parseDate(input) { var parts = input.match(/(\d+)/g); // note parts[1]-1 return new Date(parts[2], parts[1]-1, parts[0]); } parseDate('31.05.2010'); // Mon May 31 2010 00:00:00 Edit: For handling a variable format you could do something like this:
function parseDate(input, format) { format = format || 'yyyy-mm-dd'; // default format var parts = input.match(/(\d+)/g), i = 0, fmt = {}; // extract date-part indexes from the format format.replace(/(yyyy|dd|mm)/g, function(part) { fmt[part] = i++; }); return new Date(parts[fmt['yyyy']], parts[fmt['mm']]-1, parts[fmt['dd']]); } parseDate('05.31.2010', 'mm.dd.yyyy'); parseDate('31.05.2010', 'dd.mm.yyyy'); parseDate('2010-05-31'); The above function accepts a format parameter, that should include the yyyy mm and dd placeholders, the separators are not really important, since only digits are captured by the RegExp.
You might also give a look to DateJS, a small library that makes date parsing painless...
It's easy enough to split the string into an array and pass the parts directly to the Date object:
var str = "01.01.2010"; var dmy = str.split("."); var d = new Date(dmy[2], dmy[1] - 1, dmy[0]); 
There is no built in way to manipulate dates the way you would like.
The jQuery-UI datepicker has the functionality you want, I'm sure many other libraries have something similar.
$.datepicker.parseDate('dd.mm.yy', '31.12.2007'); 
t="01.01.1970" parts = t.split("."); for(var i = 0; i < parts.length; i++) parts[i] = parseInt(parts[i], 10); new Date(parts[2], parts[1]-1, parts[0]); Date defined as (Year, Month, Date)
Date()'s month parameter takes Month in Zero based index. January = 0, february = 1, march = 2... etc
Parsing the string to an int isn't necessary, but I dislike passing strings into functions and just hoping that JavaScript will "get it"... Sort of like how some people prefer ===
parseInt shouldn't be required (JavaScript's typing is dynamic and strings should automatically be cast to a number) and the loop is a bit OTT for such a simple operation.
Date constructor will explicitly convert the arguments internally ToNumber. Also, using parseInt without the radix argument, is specially harmful here, since you can have a date like "09.09.2010", and parseInt('09') == 0, since the preceding zero will force the number conversion as octal base, and this doesn't happen with the internal ToNumber operation.Building on CMS answer, I created this function to deal with a variable format
function parseDate(input, format) { format = format || 'yyyy-mm-dd'; // default format //Change from PHP date format to JS if (format == 'd/m/Y') { format = 'dd/mm/yyyy'; } if (format == 'd/m/Y H:i:s') { format = 'dd/mm/yyyy hh:ii:ss'; } let date = NaN; if (format == 'dd/mm/yyyy') { let parts = input.match(/(\d+)/g), i = 0, fmt = {}; // extract date-part indexes from the format format.replace(/(yyyy|dd|mm)/g, function(part) { fmt[part] = parts[i++]; }); //create date for new format let createdDate = new Date(fmt['yyyy'], fmt['mm']-1, fmt['dd']); //check if dates are equal by comparing parts. The issue I had here was //when I passed an invalid value for month, the output was adjustement to //accomodate for the extra months if ( createdDate.getFullYear() == fmt['yyyy'] && createdDate.getMonth() == (fmt['mm']-1) && createdDate.getDate() == fmt['dd'] ) { date = createdDate; } } //same but taking into account hours minute and seccond if (format == 'dd/mm/yyyy hh:ii:ss') { let parts = input.match(/(\d+)/g), i = 0, fmt = {}; // extract date-part indexes from the format format.replace(/(yyyy|dd|mm|hh|ii|ss)/g, function(part) { fmt[part] = parts[i++]; }); let createdDate = new Date( fmt['yyyy'], fmt['mm']-1, fmt['dd'], fmt['hh'], fmt['ii'], fmt['ss'] ); if ( createdDate.getFullYear() == fmt['yyyy'] && createdDate.getMonth() == (fmt['mm']-1) && createdDate.getDate() == fmt['dd'] && createdDate.getHours() == fmt['hh'] && createdDate.getMinutes() == fmt['ii'] && createdDate.getSeconds() == fmt['ss'] ) { date = createdDate; } } return date; } Update Oct 2023
As per Documentation:
moment(...) is local mode. Ambiguous input (without offset) is assumed to be local time. Unambiguous input (with offset) is adjusted to local time.
So it is better to always specify a timezone:
let myDateVanilla = new Date("08.06.2023"); console.log(myDateVanilla); //"2023-08-05T22:00:00.000Z" -> Not correct let myDateMoment = moment.tz("08.06.2023", "DD.MM.YYYY", "America/Los_Angeles").toDate(); console.log(myDateMoment); //"2023-06-07T22:00:00.000Z"-> Correct<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.4/moment.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.43/moment-timezone-with-data.js"></script>Also beware of the difference of these two lines:
moment.tz(date, format, timezone) moment(date, format).tz(timezone) The first one get the date in the timezone specified as parameter, the second one assumes the timezone from the browser and converts it to the timezone passed as parameter.
Previous Answer
You can use MomentJs in the following way. The example tries to convert the 8th Jun 2023
let myDateVanilla = new Date("08.06.2023"); console.log(myDateVanilla); //"2023-08-05T22:00:00.000Z" -> Not correct let myDateMoment = moment("08.06.2023", "DD.MM.YYYY").toDate(); console.log(myDateMoment); //"2023-06-07T22:00:00.000Z"-> Correct<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.4/moment.min.js"></script>Please bewhare of the ouput, you may see a different day than the 8th Jun 2023 because of timezone
Modified version of the accepted answer which supports value and format without 'dd' and uppercase format
function parseDate(input, format) { format = (format || 'yyyy-mm-dd').toLowerCase(); // default format var parts = input.match(/(\d+)/g), i = 0, fmt = {}; // extract date-part indexes from the format format.replace(/(yyyy|dd|mm)/g, function(part) { fmt[part] = i++; }); return new Date([parts[fmt['yyyy']], parts[fmt['mm']], parts[fmt['dd']]].filter(x => x !== undefined).join('-')); } parseDate('10/2018', 'MM/YYYY') 
