JavaScript calculating date from today date to 7 days before

Question

I am calculating 12 days before date from today date. But it does not return the correct date. For example, for today dat, 11/11/2013 in (mm/dd/yyyy), it returns 10/30/2013 when it should return 10/31/2013.

Here is the code

var d = new Date(); d.setDate(d.getDate() - 12); d.setMonth(d.getMonth() + 1 - 0); var curr_date = d.getDate(); var curr_month = d.getMonth(); var curr_year = d.getFullYear(); if (curr_month < 10 && curr_date < 10) {     var parsedDate = "0" + curr_month + "/" + "0" + curr_date + "/" + curr_year;     alert(parsedDate); } else if (curr_month < 10 && curr_date > 9) {     var parsedDate = "0" + curr_month + "/" + curr_date + "/" + curr_year;     alert(parsedDate); } else if (curr_month > 9 && curr_date < 10) {     var parsedDate = curr_month + "/" + "0" + curr_date + "/" + curr_year;     alert(parsedDate); } else {     var parsedDate = curr_month + "/" + curr_date + "/" + curr_year;     alert(parsedDate); } 

Answer 1

Problem is solved

var days; // Days you want to subtract var date = new Date(); var last = new Date(date.getTime() - (days * 24 * 60 * 60 * 1000)); var day =last.getDate(); var month=last.getMonth()+1; var year=last.getFullYear(); 

Answer 2

Pure js one line solution:

new Date(Date.now() - 7 * 24 * 60 * 60 * 1000)  // Tue Feb 04 2020 13:50:37 GMT... 

1. new Date() - create Date object from calculated milliseconds time.
2. Date.now() - gives time in milliseconds from 1970.
3. 7 (days) * 24 (hours) * 60 (minutes) * 60 (seconds) * 1000 (milliseconds ) = 604800000 or 7 days in milliseconds.

You can use calculated value if you have no plans to change substracted value, or computed for easy change of substracted amount of days, minutes and so on.

---

If you plan to work more often with dates and time, I recommend to use date-fns or dayjs. date-fns seems to be better

const subDays = require('date-fns/subDays') subDays(new Date(), 7) 

P.S. Why not moment.js? Moment.js is considered to be a legacy project in maintenance mode. It is not dead, but it is indeed done. See https://momentjs.com/docs/#/-project-status/