cakePHP use of I18 Time addMinutes function updates every related variable, not just the current instance

I’ve been trying to set start times for different flights of competitors. The addMinutes function seems to update every variable associated with the “ONE” I’m trying to alter. Is this the expected result, or am I missing something really simple?

Thanks for your assistance,

public function test_i18_addminutes( $a_time = null )
{
    $b_time = $a_time ?: Time::now();

    for ( $i = 1; $i < 5; $i++ ) {
        $use_time = $b_time;
        debug( "BTIME: $b_time   USETIME: $use_time" );

        for ( $j = 1; $j < 7; $j++ ) {
            $mytime = $use_time->addMinutes( 15.0 );
            debug( "     MYTIME: $mytime      BTIME: $b_time   USETIME: $use_time" );
        }
    }
    $this->redirect( '/' );
}

srcControllerTestsController.php (line 89)

‘BTIME: 9/14/21, 6:09 PM USETIME: 9/14/21, 6:09 PM’

‘ MYTIME: 9/14/21, 6:24 PM BTIME: 9/14/21, 6:24 PM USETIME: 9/14/21, 6:24 PM’

‘ MYTIME: 9/14/21, 6:39 PM BTIME: 9/14/21, 6:39 PM USETIME: 9/14/21, 6:39 PM’

‘ MYTIME: 9/14/21, 6:54 PM BTIME: 9/14/21, 6:54 PM USETIME: 9/14/21, 6:54 PM’

‘ MYTIME: 9/14/21, 7:09 PM BTIME: 9/14/21, 7:09 PM USETIME: 9/14/21, 7:09 PM’

‘ MYTIME: 9/14/21, 7:24 PM BTIME: 9/14/21, 7:24 PM USETIME: 9/14/21, 7:24 PM’

‘ MYTIME: 9/14/21, 7:39 PM BTIME: 9/14/21, 7:39 PM USETIME: 9/14/21, 7:39 PM’

‘BTIME: 9/14/21, 7:39 PM USETIME: 9/14/21, 7:39 PM’

‘ MYTIME: 9/14/21, 7:54 PM BTIME: 9/14/21, 7:54 PM USETIME: 9/14/21, 7:54 PM’

‘ MYTIME: 9/14/21, 8:09 PM BTIME: 9/14/21, 8:09 PM USETIME: 9/14/21, 8:09 PM’

Answer

All your variables, a_time, b_time, and use_time, point to the same object. Furthermore CakeI18nTime is mutable, so $mytime will also be the very same object.

If you want immutable time objects, use CakeI18nFrozenTime instead. The time manipulation methods of those objects will return new instances.

See also

• Cookbook > Date & Time > Immutable Dates and Times