时间段占工作日的百分比

Question

I need to calculate what percentage of the business day certain period of time is.

To get business day duration I use a query like this:

SELECT 
    timeOpen,
    timeClose,
    TIMEDIFF(timeClose, timeOpen) AS hours
FROM businessHours

The results I get are in the following format: HH:MM, like 11:00 or 10:30.

I'm a bit confused how to calculate what percentage another time period, like 4 hrs is of the business day hours is when I have half-hour values, like 10:30. I do not have other minutes, i.e. either even or half-hour.

Other than that I think my math will be something like this:

(4 x 100) / 10.5

Do I need to use some sort of str_replace to convert time to integer?

Answer 1

You can transform the hours to decimal in order to do arithmetic with them. In order to do this, you need to explode each hour by :, and add the first element to the second divided by 60.

After that you'll have numbers you can do math with:

<?php
$timestamp1 = "10:30";
$timeArray1 = explode(":", $timestamp1);
$timeInDecimal1 = $timeArray1[0] + $timeArray1[1]/60;
$timestamp2 = "4:00";
$timeArray2 = explode(":", $timestamp2);
$timeInDecimal2 = $timeArray2[0] + $timeArray2[1]/60;
var_dump($timeInDecimal2/$timeInDecimal1);

Demo