phpdateaddition

PHP Add 0.1 to 0 value for every two weeks past a specified date?

I'm looking to add .1 to the initial value of 0 every two weeks past a specified date.

Example: Date = 05-26-2024; InitVal = 0; AddVal = 0.1; The 26th was 4 weeks ago from 06-23-2024 which means 0 should now be 0.2.

I have had no luck finding something that would work here, or something I understand at least, on the internet so I come to you for help!

I've looked at several codes but they didn't quite fit what I was trying to do and I am incapable of actually modifying them to my needs. This is for a personal website and I just want to keep track of certain projects in a specific way.

Solution

  • PHP's time() and strtotime() both reports time in seconds. To know how many weeks there are between your specified date and now we can do:

    $startDate     = '2024-05-26 00:00:01';
$secondsInWeek = 60 * 60 * 24 * 7;
$weekDiff      = (time() - strtotime($startDate)) / $secondsInWeek;

    At this moment $weekDiff would be around 4.125.

    You want to add 0.1 to an initial value each two weeks:

    $initial  = 0.0;
$increase = 0.1;
$stepNo   = intdiv(floor($weekDiff), 2);
$value    = $initial + $stepNo * $increase;

    Which will result in an $value of 0.2. See: https://3v4l.org/gZgeY

    Rounding down $weekDiff with floor() results in 4.0. And dividing by 2 integer gives 2. Using this as a step number you can calculate your value. Note that intdiv() will always return the lower whole number, which is an integer. So intdiv(3.5,2) is 1.

    If you happen to get a warning like:

    Warning: Implicit conversion from float to int loses precision

    You can use intval() for the argument.