Online PHP editor | output for JbKKW

@ 2019-02-12T20:22:33Z

<?php

date_default_timezone_set('Europe/London');

$date3 = DateTime::createFromFormat('Y-m-d H:i:s', '2019-04-01 00:00:00'); //  2019-04-01 00:00:00.0 Europe/London (+01:00)
$date4 = clone $date3;
$date4->modify('+5 week'); // 2019-05-06 00:00:00.0 Europe/London (+01:00)
echo "So the originally modified date with 5 weeks added is:";
print_r($date4);

echo "\n\n";

// positive DIFF and addition
echo "1. positive DIFF and addition\n";
echo "diff is: ";
$positiveDifferenceDateInterval2 = $date3->diff($date4); // interval: + 1m 4d; days 35
print_r($positiveDifferenceDateInterval2->format('%R %mm %dd'));
echo "; days: {$positiveDifferenceDateInterval2->days} \n";
$positiveAddedDate = clone $date3;
$positiveAddedDate->add($positiveDifferenceDateInterval2);
print_r($positiveAddedDate);
echo "is it equal to \$date4? ";
var_dump($date4->getTimestamp() === $positiveAddedDate->getTimestamp());
echo "\n";

// negative DIFF and addition
echo "2. negative DIFF and addition\n";
echo "diff is: ";
$negativeDifferenceDateInterval2 = $date4->diff($date3); // interval: - 1m 5d; days 35
print_r($negativeDifferenceDateInterval2->format('%R %mm %dd'));
echo "; days {$negativeDifferenceDateInterval2->days}";
$negativeAddedDate = clone $date3;
// so in order to make it equal to $date4 I need to subtract a negative interval instead of adding a positive one? how crazy is that?!
$negativeAddedDate->sub($negativeDifferenceDateInterval2); 
print_r($negativeAddedDate);
echo "is it equal to \$date4? ";
var_dump($date4->getTimestamp() === $negativeAddedDate->getTimestamp());
echo "\n\n";

echo 'so in order to make it equal to $date4 I need to subtract a negative interval instead of adding a positive one? how crazy is that?!';

Output for 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.4, 8.3.6 - 8.3.7: So the originally modified date with 5 weeks added is:DateTime Object ( [date] => 2019-05-06 00:00:00.000000 [timezone_type] => 3 [timezone] => Europe/London ) 1. positive DIFF and addition diff is: + 1m 5d; days: 35 DateTime Object ( [date] => 2019-05-06 00:00:00.000000 [timezone_type] => 3 [timezone] => Europe/London ) is it equal to $date4? bool(true) 2. negative DIFF and addition diff is: - 1m 5d; days 35DateTime Object ( [date] => 2019-05-06 00:00:00.000000 [timezone_type] => 3 [timezone] => Europe/London ) is it equal to $date4? bool(true) so in order to make it equal to $date4 I need to subtract a negative interval instead of adding a positive one? how crazy is that?!
Output for 8.3.5: Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0 So the originally modified date with 5 weeks added is:DateTime Object ( [date] => 2019-05-06 00:00:00.000000 [timezone_type] => 3 [timezone] => Europe/London ) 1. positive DIFF and addition diff is: + 1m 5d; days: 35 DateTime Object ( [date] => 2019-05-06 00:00:00.000000 [timezone_type] => 3 [timezone] => Europe/London ) is it equal to $date4? bool(true) 2. negative DIFF and addition diff is: - 1m 5d; days 35DateTime Object ( [date] => 2019-05-06 00:00:00.000000 [timezone_type] => 3 [timezone] => Europe/London ) is it equal to $date4? bool(true) so in order to make it equal to $date4 I need to subtract a negative interval instead of adding a positive one? how crazy is that?!
Output for 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30: So the originally modified date with 5 weeks added is:DateTime Object ( [date] => 2019-05-06 00:00:00.000000 [timezone_type] => 3 [timezone] => Europe/London ) 1. positive DIFF and addition diff is: + 1m 4d; days: 35 DateTime Object ( [date] => 2019-05-05 00:00:00.000000 [timezone_type] => 3 [timezone] => Europe/London ) is it equal to $date4? bool(false) 2. negative DIFF and addition diff is: - 1m 5d; days 35DateTime Object ( [date] => 2019-05-06 00:00:00.000000 [timezone_type] => 3 [timezone] => Europe/London ) is it equal to $date4? bool(true) so in order to make it equal to $date4 I need to subtract a negative interval instead of adding a positive one? how crazy is that?!

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