Calculating Total Overtime Working Hours using Condition - php

Question

Need your help with my case.
How to make calculating total overtime working hours using condition ?
Example :
using input type,
OT From <input type="text" name="ot_from">
OT To <input type="text" name="ot_to">
Total Hours <input type="text" name="total_hours">
Working days : from 08.00 - 17.00 (normal working days)
If I working until 19.00, should be calculate that I do overtime for 2 hours.
In my rules, from 18.00 - 18.30 not calculate overtime because that's a break time.
So should be my total Overtime hours is 1.5 not 2 hours.
Someone can give me a solution ?
Appreciate your help.
Thank you.
David

Answer 1

Here is what you should do:
1 Split the hours and minutes into a total amount of minutes.
str = "1:23" or other time value
time = parseInt(str.split(":")[0], 10)*60+parseInt(str.split(":")[1], 10)
2 Subtract the finish time from the start time - this will give you the final time.
3 To convert from minutes to hours do the following:
minutes = time%60
hours = parseInt(time/60, 10)
You don't actually need PHP - this can all be done with Javascript, as long as you are not looking to store the data in a database or anything.

Answer 2

If you want to make sure the input of the user is always equal, you should replace the input fields with Select boxes. Then you can make one Select box for the hours and one for the minutes.
To calculate the working hours, you can do a basic calculation like this:
<?php
// Vars of the POST form
$otfrom_hours = $_POST['ot_from_hours'];
$otfrom_minutes = $_POST['ot_from_minutes'];
$otto_hours = $_POST['ot_to_hours'];
$otto_minutes = $_POST['ot_to_minutes'];
// Make a full string for strtotime
$otfrom_string = $otfrom_hours.":".$otfrom_minutes;
$otto_string = $otto_hours.":".$otto_minutes;
// Basic calculation
$start = strtotime($otfrom_string);
$end = strtotime($otto_string);
$elapsed = $end - $start;
echo date("H:i", $elapsed);
?>
Hope it will be usefull!