How to reformat the date in the desired form?

Question

JavaScript

Through the field, the date from the field gets into js (not a field specifically for the date, but a regular input). And there may be different forms, but for the api you need to reduce everything to YYYY-MM-DD (the api is not mine, I can’t change it). How to implement this in js without using a calendar?

Answer 1

The simplest thing is to include the moment library (or an analogue of day-fns, etc.)
to get the date in the required format:

const formatedDate = moment(sourceDate).format('YYYY-MM-DD')

Also, to set the format for parsing the date (if a string comes from the input), you need to pass the string with the format as the second argument to the moment function: If it is required without a moment, then write your own implementation using the Date class
const date = moment(dateString, 'DD-MM-YYYY')