How to get time between two specific time period - php

Question

What I am doing is actually iterating from 8AM to 9PM with 1 hour interval but it doesn't give me correct result. This is my code below
<?php
$date = date("08:00");
for($i=1; $i<=10; $i++)
{
$date = strtotime("+".$i." hour");
echo date('H:i A', $date);
}
?>
it starts with current time!,
Thanks for your help.

Answer 1

There are a few different problems to unpack here:
$date = date("08:00");
This isn't useful. date is for formatting a timestamp - you can't use it to create one from an hours:minutes string like this.
What you probably want is
$date = strtotime("08:00");
The reason this didn't cause any problems is that inside your loop you then immediately overwrite it with:
$date = strtotime("+".$i." hour");
This will create a new timestamp, but it will be relative to now, not your initial time. Saying "+1 hour" means you want a timestamp that is now + 1 hour. You can use strtotime to create a timestamp relative to another by using the second argument...
$date = strtotime("+{$i} hour", $date);
...but you're still overwriting your start value. So let's put that in a variable called $start instead:
$start = strtotime("08:00");
...
$date = strtotime("+".$i." hour", $start);
This gets you:
<?php
$start = strtotime("08:00");
for($i=0; $i<=10; $i++) {
$date = strtotime("+{$i} hour", $start);
echo date('H:i A', $date), PHP_EOL;
}
which will output:
08:00 AM
09:00 AM
10:00 AM
...
18:00 PM
It doesn't quite get you to 9PM, because that's not ten hours away from 8am, but 13. I'll leave the last part to you.
See https://eval.in/867974
Also, you might want to look at PHP's DateTime library, which gives you an object-oriented interface for working with dates & times. For a simple script like this, it's not vital.