PHP : Check for overlapping time range in an array? - php

Question

I am trying to work out if two time ranges in PHP overlap in same array.If a time range is nested in between the start and end times of another time range, it's not being matched.
Array
(
[1] => Array
(
[start_time] => 01:00
[end_time] => 04:00
)
[2] => Array
(
[start_time] => 05:00
[end_time] => 08:00
)
[3] => Array
(
[start_time] => 06:00
[end_time] => 12:00
)
[4] => Array
(
[start_time] => 13:00
[end_time] => 24:00
)
)

Answer 1

To compare two date/times you have to convert them first into \DateTime objects.
Then you have to do a simple comparison with < and > operators.
But what you are trying to achieve is not to get Date/Times but simply compare hours.
So, as they are simple string, you should first convert them in numbers.
The best thing you can do is to convert all of them into minutes, and then compare them.
So, something like this should work:
function convertFromHoursToMinutes($string)
{
// Separate hours from minutes
$split = explode(':', $string);
// Transform hours into minutes
$hoursToMinutes = $split[0] * 60;
$total = $hoursToMinutes + (int)$split[1];
return $total;
}
$ranges = [
[
'start_time' => '01:00',
'end_time' => '04:00'
],
[
'start_time' => '05:00',
'end_time' => '08:00'
],
[
'start_time' => '06:00',
'end_time' => '12:00'
],
[
'start_time' => '13:00',
'end_time' => '24:00'
]
];
foreach ($ranges as $range)
{
// Convert values into minutes
$start_time = convertFromHoursToMinutes($range['start_time']);
$end_time = convertFromHoursToMinutes($range['end_time']);
// Do the comparison
if ($start_time > $end_time)
{
echo 'Start > end';
} else {
echo 'Start < end';
}
echo '<hr />';
}