JavaScript date range between date range

Question

I'm trying to have an IF check to see if X date range is between Y date range. But it's not returning the correct true/false on the correct time:

var startdate = new Date('06/06/2013');
var enddate = new Date('06/25/2013');
var startD = new Date('06/08/2013');
var endD = new Date('06/18/2013');

if(startD >= startdate || endD <= enddate) {
  return true;
} else {
  return false;
}

This works, but if I change startdate to 06/09/2013 and enddate to 06/17/2013 it no longer works while it should work.

It should even work if startdate was 06/07/2013 and enddate was 06/15/2013, but doesn't. Any thoughts?

Are you trying to detect if the date ranges overlap, or if one is fully contained within another? — voithos
– voithos, Commented Jun 25, 2013 at 18:07
For a date range to be a subset of another date range, the start of the inner range must be after the start of the outer range AND the end of the inner range must be before the end of the outer range. Do you want to check that one range contains another in its entirety, or do you want to detect if they overlap? — zzzzBov
– zzzzBov, Commented Jun 25, 2013 at 18:07
Both and either one really. As if enddate is within the range it needs to be included as some days will overlap. If startdate is within the range but enddate goes out it still needs to be true as a few days will still be within the range. So both really. — jfreak53
– jfreak53, Commented Jun 25, 2013 at 18:10
@jfreak53: You say both, but you're basically looking for overlap. Being fully contained within another date range is still an overlap. — voithos
– voithos, Commented Jun 25, 2013 at 18:12
And you might also consider using half-open intervals. Inclusive start dates (>=) but exclusive end dates (<). Otherwise, you may get overlaps that you didn't actually want. Read more here. — Matt Johnson-Pint
– Matt Johnson-Pint, Commented Jun 25, 2013 at 18:21

voithos · Accepted Answer · 2013-06-25 18:33:38Z

44

If you're trying to detect full containment, that is fairly easy. (Also, you don't need the explicit return true/false, because the condition is a boolean anyway. Just return it)

// Illustration:
//
// startdate                          enddate
// v                                        v
// #----------------------------------------#
//
//         #----------------------#
//         ^                      ^
//         startD              endD
return startD >= startdate && endD <= enddate;

An overlap test is slightly more complex. The following will return true if the two date ranges overlap, regardless of order.

// Need to account for the following special scenarios
//
// startdate     enddate
// v                v
// #----------------#
//
//         #----------------------#
//         ^                      ^
//         startD              endD
//
// or
//
//              startdate        enddate
//                 v                v
//                 #----------------#
//
//         #------------------#
//         ^                  ^
//       startD              endD
return (startD >= startdate && startD <= enddate) ||
       (startdate >= startD && startdate <= endD);

@Bergi's answer is probably more elegant, in that it just checks the start/end pairs of the two date ranges.

edited Jun 25, 2013 at 18:33

answered Jun 25, 2013 at 18:17

voithos

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3 Comments

Bergi Over a year ago

Well, if you would allow containment in overlapping the test would be much easier…

voithos Over a year ago

@Bergi: I'm not entirely sure what you mean by "if you would allow containment" - I'm pretty sure this still returns true when ranges are completely contained. But I agree that it's more elegant to check for start/end pairs.

user1693593 Over a year ago

Tip: compare using startD.getTime() instead of just the date object as using the date object will convert to string first and compare as string, as getTime() compares integer values which is more than 10x faster (in FF, 20x in Chrome) - of course not vital unless one need to compare a lot of dates. Non-scientific test: jsperf.com/test-time-vs-gettime

Bergi · Accepted Answer · 2013-06-25 18:16:51Z

26

To check if they overlap with any days, use

if (endD >= startdate && startD <= enddate)

which is equivalent to

if ( !(endD < startdate || startD > enddate)) // not one after the other

answered Jun 25, 2013 at 18:16

Bergi

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Comments

Bungus · Accepted Answer · 2013-06-25 18:14:12Z

16

In your example, the new dates are both outside the range.

If you want to check if there is any overlap between the date ranges, use:

return (endD >= startdate && startD <= enddate);

answered Jun 25, 2013 at 18:14

Bungus

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1 Comment

Bungus Over a year ago

@voithos - Seeing as this answer is the same as Bergi, but 2 minutes earlier, and I'm just starting out on reps...

Abdulaziz Alsubaie · Accepted Answer · 2021-02-27 10:08:24Z

here is the logic in nodejs

    export const isDateOverlaped = (firstDateRange: { from: Date; to: Date }, secondDateRange: { from: Date; to: Date }) => {
  // f-from -----------f-to
  //          s-from -------------- s-to
  const overlappedEnd =
    firstDateRange.from <= secondDateRange.from && firstDateRange.to >= secondDateRange.from && firstDateRange.to <= secondDateRange.to

  // f-from ----------------------- f-to
  //          s-from --------- s-to
  const overlappedBetween = firstDateRange.from <= secondDateRange.from && firstDateRange.to >= secondDateRange.to

  //            f-from -----------f-to
  // s-from -------------- s-to
  const overlappedStart =
    firstDateRange.from >= secondDateRange.from && firstDateRange.from <= secondDateRange.to && firstDateRange.to >= secondDateRange.to

  return overlappedEnd || overlappedBetween || overlappedStart
}

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