Your first mistake is using Javascript's Date. Js Joda is the only datetime library that doesn't make me wanna cry -> https://js-joda.github.io/js-joda/ https:

Your first mistake is using Javascript's Date. Js Joda is the only datetime library that doesn't make me wanna cry -> https://js-joda.github.io/js-joda/ https://js-joda.github.io/js-joda/ It is kinda similar to the new Temporal api: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe... Or if you want to live on the edge: https://www.npmjs.com/package/temporal-polyfill https://www.npmjs.com/package/temporal-polyfill For experiments, I would strongly suggest to look into Temporal API.