30-seconds-of-code/snippets/addDaysToDate.md

title, tags

title	tags
addDaysToDate	date,beginner

Return the date of n days from any given date.

• Use new Date() to read the first parameter as a valid Date
• Add n number of days to the given date
• Return the output in yyyy-MM-dd format by using Date.prototype.toISOString() and removing timestamp
• For example, adding 15 to 1 October 2020 results to 16 October 2020
• Also accepts negative numbers. For example, adding -15 to 16 October 2020 results to 1 October 2020

const addDaysToDate = (d,n) => {
  d = new Date(d);
  d.setDate(d.getDate() + n);
  return d.toISOString().split('T')[0];
}

addDaysToDate("2020-10-15", -10); // '2020-10-05'
addDaysToDate("2020-10-15", 10); // '2020-10-25'
addDaysToDate("10/15/2020", 10); // '2020-10-25'
addDaysToDate("2020-10-31", 1); // '2020-11-01'
addDaysToDate("12/31/2020", 31); // '2021-01-31'