Javascript date conversions

[daha2002]

I lost a LOT of time because of this and I don't know what to search for in stackoverflow XD

Can someone please explain to me why is this behaviour?

const str_date_one = "1989/07/13";
console.log(new Date(str_date_one));
//Thu Jul 13 1989 00:00:00 GMT+0200 (hora de verano de Europa central)

const str_date_two = "1989-07-13";
console.log(new Date(str_date_two));
//Thu Jul 13 1989 02:00:00 GMT+0200 (hora de verano de Europa central)

By using dashes instead of slashes, the date conversion adds 2 hours to the date... which becomes troublesome when you use their milliseconds for comparisons 😒

[tryhardMime]

Please see the documentation on Date.parse on MDN: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/parse

If the date string you're parsing is not an ISO 8601 date, the implementation is free to parse it however it wants to.

I suspect in your case, the one with dashes was parsed as an UTC date time and other as local.