Alarm sound at certain time of a day - php

Question

The idea is to play an alarm from html/php web-page via a TV hanging near the school canteen reminding students to wash their hands. The TV is used as a tabloid screen for school events and news.
The piece of code I'm using on this page is as follows:
<?php
$hour = date('G');
$day = date('1..5'); // 1..7 for Monday to Friday
if (($hour >= 11.05 && $hour <= 11.35) // 5am - 7am
|| ($hour >= 12.15 && $hour <= 12.30) // 10am - 12 noon
|| ($hour >= 21.10 && $hour <= 21.30) // 10am - 12 noon
|| ($day == 1-5) // Monday - Friday
) { ?>
<audio src="Audio/sirena.mp3" autoplay="true" loop="loop">
<?php } ?>
This only plays it once the page is uploaded onto the server, and if it falls within the times above. Otherwise, it stays silent. And, strangely it plays only on my home PC on Chrome/IE/Mozilla and it doesn't play completely on school PCs.
Bear in mind the page auto refreshes itself every 5 min.
Would appreciate if someone gave a hint on event listeners or anything else.

Answer 1

There are a couple of problems with your code.
In $day = date('1..5');, '1..5' isn't a valid format for date(). That will just return the string 1..5. You want date('w').
date('G') returns the hour in 24-hour format, so $date will be a string representation of an integer. In your if condition you are comparing it to floats. Since all of the different time conditions are various decimals above the same integers, $date will never match any of them. For example, if the time is 11:30 AM, $date will be '11', which is not between 11.05 and 11.35. (Obviously, neither is '10' or '12'.)
In the last part of the if condition, you have || ($day == 1-5). There are two problems with that. First, 1-5 does not mean "between one and five"; it means "one minus five". And second, the fact that this is an additional non-nested or condition means that it negates all of the various time comparisons, because whenever any part of an or condition is true, the entire condition evaluates to true. If it was || ($day >= 1 && $day <= 5), then the if would be true all day every Monday through Friday. As it is, it's true all day only on Thursday.
I added an updated version that I think will do what you want it to (based on the comments in your code). I used some kind of strange indentation in the if condition to hopefully show the grouping a little better. Basically it needs to check the day and check a group of time conditions. Note the different format for time ('Gi'), which gets the hour and minute in a format that can be compared to integer values in the if condition.
$day = date('w');
$time = date('Gi');
if ( ($day > 0 && $day < 6) // Monday - Friday
&& ( // AND
($time >= 1105 && $time < 1135) // time range 1
|| // OR
($time >= 1215 && $time < 1230) // time range 2
|| // OR
($time >= 2110 && $time < 2130) // time range 3
)
)
echo '<audio src="Audio/sirena.mp3" autoplay="true" loop="loop">';