I have done almost everything I found on the internet. I have been trying for the past two days but couldn't get the desire answer. I just want to subtract two times. example 22:00:00 - 00:30:00 = 21:30:00
$hourToEatLastMeal = strtotime('00:30:00');
$hourToEatWorkout = strtotime('01:30:00');
$hourBetweenMeal = strtotime('07:30:00');
$lastMealRequested = strtotime($row['lastMeal']); //22:00:00 //value getting from query.
$startEating = $lastMealRequested - $hourToEatLastMeal ;//21:30:00 (want this answer)
$timeToEat = $startEating- $hourBetweenMeal; //14:00:00 (want this answer)
$whenToWorkout = $timeToEat - $hourToEatWorkout; //12:30:00 (want this answer)
$whenToWorkout = date("H:i:s",($whenToWorkout));//12:30:00 (want this answer)
$timeToEat = date("H:i:s",($timeToEat));//14:00:00 (want this answer)
$startEating = date("H:i:s",($startEating));//21:30:00 (want this answer)
00:30:00 is half past midnight, not 30 minutes. You can subtract 30 minutes with the strtotime function by using -30 minutes.
echo date('H:i:s', strtotime('22:00:00 -30 minutes'));
Other intervals can be done similarly:
echo date('H:i:s', strtotime('22:00:00 -1 hour -30 minutes'));
In your recent example you'd want:
echo date('H:i:s', strtotime($lastMealRequested . ' -30 minutes'));
because you want the strtotime to do the math, not PHP (or not PHP directly).
As others have pointed out 00:00:30 isn't 30 minutes; it's half past 12 (midnight).
If you keep in mind that strotime() returns a Unix timestamp (i.e.: the number of seconds since January 1 1970 00:00:00 UTC), you should be able to work it out:
<?php
function timeDiff( $t1, $t2, $echo = true ) {
if ( $t2 > $t1 ) {
$temp_time = $t2;
$t2 = $t1;
$t1 = $temp_time;
unset( $temp_time );
}
$diff = $t1 - $t2;
$hours = floor( $diff / 3600 );
$minutes = $diff % 3600 / 60;
$timeFormatted = "$hours:$minutes:00";
if ( $echo ) {
echo $timeFormatted . '<br />';;
}
return strtotime( $timeFormatted );
}
$hourToEatLastMeal = strtotime( '00:30:00' );
$hourToEatWorkout = strtotime( '01:30:00' );
$hourBetweenMeal = strtotime( '07:30:00' );
$lastMealRequested = strtotime( '22:00:00' ); //22:00:00 //value getting from query.
$startEating = timeDiff( $lastMealRequested, $hourToEatLastMeal );//21:30:00 (want this answer)
$timeToEat = timeDiff( $startEating, $hourBetweenMeal ); //14:00:00 (want this answer)
$whenToWorkout = timeDiff( $timeToEat, $hourToEatWorkout ); //12:30:00 (want this answer)
This is far from ideal, though. It's better to have strtotime() do the math. You could explode() the value you're substracting to get the hours and minutes:
function timeDiff( $t1, $t2 ) {
$timeArr = explode( ':', $t2 );
return strtotime( $t1 . " - {$timeArr[0]} hour - {$timeArr[1]} minutes" );
}
echo date( "H:i:s", timeDiff( '22:00:00', '00:30:00' ) );
$hourToEatLastMeal = '-30 minutes';
$hourToEatWorkout = '- 1 hour - 30 minutes';
$hourBetweenMeal = '- 7 hours - 30 minutes';
$lastMealRequested = new \DateTimeImmutable($row['lastMeal']);
$startEating = $lastMealRequested->modify($hourToEatLastMeal);
$timeToEat = $startEating->modify($hourBetweenMeal);
$whenToWorkout = $timeToEat->modify($hourToEatWorkout);
echo $whenToWorkout->format('H:i:s') . PHP_EOL;
echo $timeToEat->format('H:i:s') . PHP_EOL;
echo $startEating->format('H:i:s') . PHP_EOL;