If you run this JavaScript function on the 31st of a month, the result will be a month off. The best part is that this is the intended behvaior. JavaScript is a cursed language.

posted 1 year ago

function getMonthName(monthNumber) {
  const date = new Date();
  date.setMonth(monthNumber - 1);

  return date.toLocaleString([], { month: 'long' });
}

The current day of month will have an impact on the behavior of this method. Conceptually it will add the number of days given by the current day of the month to the 1st day of the new month specified as the parameter, to return the new date. For example, if the current value is 31st January 2016, calling setMonth with a value of 1 will return 2nd March 2016. This is because in 2016 February had 29 days.

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towerful@programming.dev

3 points

1 year ago

The date API is like the original rip of the Java date API. Barely changed, and totally backwards compatible nonsense.

Temporal is the new JavaScript/ECMAScript date API.
It’s stage 3, and likely stable (just a few kinks being worked out). So you could polyfill it for production.
https://github.com/tc39/proposal-temporal

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