PHP时差24h时钟系统问题

Question

im trying to calculate the time between two different times and output them in hours. It will be displayed to the customer to see how much time the service will take.

Thats my code:

$datetime1 = new DateTime($timeFROM);
$datetime2 = new DateTime($timeTO);
$interval = $datetime2->diff($datetime1);
$hour_decimal = number_format(intval($interval->format('%H')) + round(intval($interval->format('%I')) / 60, 2), 2, '.','');
echo $hour_decimal;

The code works fine for classic jobs, but for work at night its getting complicated because if the second time value ($timeTO) is after 00:00 it calculates from $timeTO to $timeFROM instead of $timeFROM to $timeTO.

Example:

$timeFROM = "6:00";
$timeTO = "8:00";

output = 2.00 That would be correct.

Example 2:

$timeFROM = "23:30";
$timeTO = "1:00";

output = 22.50 And thats wrong. It should be 1.50

Looks like I need to force the function to always calculate from $timeFROM to $timeTO and not the other way around, no matter which value is bigger.

Anyone an idea? Couldn't find anything in google and also didn't know how to ask google for that exactly. Sorry when the solution might be very easy!

Greetings

Answer 1

Add 24 hours if datetime2 is less than datetime1 if you only want forward calculations:

if ($datetime2 < $datetime1) {
    $datetime2->add(new DateInterval("PT24H"));
}