Why date comparison gives wrong result?

Question

$examDay1 = date("07.02.2022");

$examDay2 = date("18.03.2022");

$examDay3 = date("06.04.2022");

$today = date("d.m.Y");

print_r($examDay1 <= $today);  //true 

print_r($examDay2 <= $today);  // false as I expected

print_r($examDay3 <= $today);  // true for some reason

I am trying to give access to users in same specific dates. For example one of them started today and the comparison worked fine. However, somehow it says $examDay3 <=$today gives true. What am I doing wrong?

Because you are comparing strings, which only works if they are ymd formatted. Does this answer your question? [How can I compare two dates in PHP?](https://stackoverflow.com/questions/3847736/how-can-i-compare-two-dates-in-php) — AD7six, Feb 07 '22 at 13:29

score 3 · Answer 1 · answered Feb 07 '22 at 13:29

The date() function in php returns a string so you can't use those operators to compare. If you want to be able to compare dates, something like this would work:

   $examDay1 = new DateTimeImmutable("07.02.2022");
   $examDay2 = new DateTimeImmutable("18.03.2022");
   $examDay3 = new DateTimeImmutable("06.04.2022");

   $today = new DateTimeImmutable('now');

   print_r($examDay1 <= $today);  //true 
   print_r($examDay2 <= $today);  // false 
   print_r($examDay3 <= $today);  // false

If you prefer the procedural style, you can use date_create_immutable() instead of new DateTimeImmutable()

score 2 · Answer 2 · answered Feb 07 '22 at 13:38

You may use dateTime class. The method DateTime::createFromFormat can be usefull. Try :

$examDay1 = DateTime::createFromFormat('j.m.Y', '07.02.2022');

$examDay2 = DateTime::createFromFormat('j.m.Y', '18.03.2022');

$examDay3 = DateTime::createFromFormat('j.m.Y', '06.04.2022');

$today = new DateTime("now");;

print_r($examDay1 <= $today);  

print_r($examDay2 <= $today);  

print_r($examDay3 <= $today);

score 2 · Answer 3 · answered Feb 07 '22 at 13:40

PHPs Date function returns a string, as stated in the documentation:

You can use "strtotime" to convert the date string to a timestamp integer, and use it for comparison.

$examDay1 = date("07.02.2022");

$examDay2 = date("18.03.2022");

$examDay3 = date("06.04.2022");

$today = time();

var_dump(
    strtotime($examDay1) <= $today,
    strtotime($examDay2) <= $today,
    strtotime($examDay3) <= $today
);

Why date comparison gives wrong result?

3 Answers3