Php – Find out if date is between two dates, ignoring year

datePHP

I need to determine if a date (month and day) is between two other month/days.

I've attached an image to this post that describes what I'm trying to do. Basically the example "current day" is highlighted in red, and it's between those nearest dates (Mar 15 and Nov 22). However, when I use Unix timestamps and artificially add a year to the dates, the script thinks that Nov 22 hasn't occurred yet, and therefore it suggests that Feb 1 is before Mar 15 AND Nov 22, instead of in between them. So, I need to compare dates without using a year.

Hopefully this makes sense. I'd just like to compare dates using months and days, but ignoring the year, and using a framework like the wheel I show in the image.

Determine if date falls between two dates

Best Answer

The problem in your example is that (in the same year) the upper bounding date is before the lower bound. In that case, Any date less than the upper bound (Jan 1 - Mar 14) or greater than the lower bound (Nov 23 - Dec 31) falls between the two.

<?php
    $upperBound = new DateTime("Mar 15");
    $lowerBound = new DateTime("Nov 22");
    $checkDate = new DateTime("Feb 1");

    if ($lowerBound < $upperBound) {
        $between = $lowerBound < $checkDate && $checkDate < $upperBound;
    } else {
        $between = $checkDate < $upperBound || $checkDate > $lowerBound;
    }
    var_dump($between);
?>

Displays: boolean true

Edit

If the date you want to check is "Feb 29" and the current year is not a leap year, then DateTime interprets it as "Mar 1".

To check if a date falls between two dates, inclusively, use:

if ($lowerBound < $upperBound) {
    $between = $lowerBound <= $checkDate && $checkDate <= $upperBound;
} else {
    $between = $checkDate <= $upperBound || $checkDate >= $lowerBound;
}

Related Solutions

Python – How to calculate number of days between two given dates

If you have two date objects, you can just subtract them, which computes a timedelta object.

from datetime import date

d0 = date(2008, 8, 18)
d1 = date(2008, 9, 26)
delta = d1 - d0
print(delta.days)

The relevant section of the docs: https://docs.python.org/library/datetime.html.

See this answer for another example.

Javascript – Compare two dates with JavaScript

The Date object will do what you want - construct one for each date, then compare them using the >, <, <= or >=.

The ==, !=, ===, and !== operators require you to use date.getTime() as in

var d1 = new Date();
var d2 = new Date(d1);
var same = d1.getTime() === d2.getTime();
var notSame = d1.getTime() !== d2.getTime();

to be clear just checking for equality directly with the date objects won't work

var d1 = new Date();
var d2 = new Date(d1);

console.log(d1 == d2);   // prints false (wrong!) 
console.log(d1 === d2);  // prints false (wrong!)
console.log(d1 != d2);   // prints true  (wrong!)
console.log(d1 !== d2);  // prints true  (wrong!)
console.log(d1.getTime() === d2.getTime()); // prints true (correct)

I suggest you use drop-downs or some similar constrained form of date entry rather than text boxes, though, lest you find yourself in input validation hell.

For the curious, date.getTime() documentation:

Returns the numeric value of the specified date as the number of milliseconds since January 1, 1970, 00:00:00 UTC. (Negative values are returned for prior times.)

Best Answer

Edit

Related Solutions

Python – How to calculate number of days between two given dates

Javascript – Compare two dates with JavaScript

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