Javascript: Select dates that fall within html5 input type="week"

Question

I have an array of dates in Javascript, and I need to filter for those that fall within a week range.

The HTML5 input tag supports type="week" which returns a string in the format YYYY-WW, i.e the four digit year, followed by a two digit ISO week date. e.g. week 2017-1falls between Monday Jan 2 2017 and Sunday Jan 8 2017 inclusive.

How do I select the dates that fall within a week specified in an html5 week input?

Code

const dates = [
  new Date('2016-12-07T22:10:50.855Z'),
  new Date('2017-01-25T09:47:15.109Z'),
  new Date('2016-12-23T17:36:26.309Z'),
  new Date('2016-12-28T22:06:22.459Z'),
  new Date('2016-12-26T14:04:12.874Z'),
  new Date('2016-12-15T06:32:42.628Z'),
  new Date('2017-01-18T08:14:43.478Z'),
  new Date('2017-01-07T03:37:54.351Z'),
  new Date('2017-01-05T04:05:52.437Z'),
  new Date('2017-01-13T20:42:04.034Z'),
  new Date('2016-12-31T10:55:47.552Z'),
  new Date('2017-01-21T02:44:11.275Z'),
  new Date('2016-12-20T18:09:35.298Z'),
  new Date('2017-01-06T11:52:59.413Z'),
  new Date('2017-01-12T02:40:56.888Z'),
  new Date('2016-12-17T03:41:15.191Z'),
  new Date('2016-12-18T01:30:40.727Z'),
  new Date('2016-12-28T08:12:10.745Z'),
  new Date('2017-01-19T11:25:56.199Z'),
  new Date('2017-01-03T13:17:14.474Z'),
  new Date('2017-01-11T07:00:57.338Z'),
  new Date('2016-12-20T01:22:55.865Z'),
  new Date('2017-01-11T23:42:48.051Z'),
  new Date('2016-12-29T20:04:20.385Z'),
  new Date('2017-01-18T13:21:48.257Z')
  ]

const week = '2017-01'

// given a date and a range
// return true if date falls within range
// otherwise return false
const fallsWithinRange(date, week) {
  // magical function yet to be discovered here
}

const filteredDates = dates.filter((date)=>fallsWithinRange(date, week));

You'd need to convert the `YYYY-WW` string into two `Date` objects — Phil, Jan 23 '17 at 23:54
@Phil you'll find all this information on the ISO Week Date wikipedia page, it's part of ISO 8601 date and time standard https://en.wikipedia.org/wiki/ISO_week_date#First_week — Amin Shah Gilani, Jan 24 '17 at 00:08

score 0 · Answer 1 · edited May 23 '17 at 12:33

Adapted from this SO answer:

const fallsWithinRange = (date, week) => {
    const y = week.split('-')[0];
    const w = week.split('-')[1];

    const startDays = 3 + (w - 1) * 7 - (new Date(y,0,1)).getDay();
    const startDay = new Date(y, 0, startDays);
    const endDays = 9 + (w - 1) * 7 - (new Date(y,0,1)).getDay();
    const endDay = new Date(y, 0, endDays);

    return (date >= startDay && date <= endDay);
};

Javascript: Select dates that fall within html5 input type="week"

Code

1 Answers1