Populate Drop Down with Time using Time Range from Database - php

Question

I am trying to populate a drop-down menu with time in 30 minute intervals (ability to change to different intervals would be nice too).
I am currently using the following code to populate the drop down (Scrounged this up online from searching around).
$sqlHours = "SELECT Open, Close FROM TimeTable";
$rsSQLHours = odbc_exec($conn, $sqlHours);
$strOpen = trim(odbc_result($rsSQLHours, "Open"));
$strClose = trim(odbc_result($rsSQLHours, "Close"));
$DeliHourOpen = substr($strOpen, 0, 2);
$DeliMinOpen = substr($strOpen, 3, 2);
$DeliHourClose = substr($strClose, 0, 2);
$DeliMinClose = substr($strClose, 3, 2);
for($hours=$DeliHourOpen; $hours<=$DeliHourClose; $hours++)
for($mins=$DeliMinOpen; $mins<60; $mins+=30)
echo '<option value='.$hours.':'.$mins.'>'.date('h:i A', strtotime($hours.':'.$mins)).'</option>'; ?>
Edit: I am storing the times in the database in 24h format, such as 08:00:00 or 22:00:00. I am using the date() just to format the displayed output in an AM/PM fashion for ease of use by users.
I am having issues when the Close Time is 20:00 it will go up to 8:30 PM in the drop-down. If I remove the = from <=$DeliHourClose then it will only display 7:30 PM. I need it to Display up to whatever the Close Time is.
The fields in the database are 'Time' in the in format 'H:i:s'.
Also, although the drop-down can be populated with a range of times from Open to Close, I need it to start at whatever the current time is + 30 minutes.
So if the Open Time is 8:00 AM, and it is 7:00 AM I want to see 8:00 AM as the first time in the drop-down. But if it is 9:00 AM, the first option in the drop-down needs to be 9:30 AM.
I have the general idea that it needs some sort of if/else to compare current time to the times in the drop-down, but I am not sure how to go about it, with the format I am using now for the drop-down.
I would prefer to have a more manageable format if possible.
Is there an easier/better way to generate a range of times with intervals that may be changed? And then populate the drop-down with the appropriate times?
Any help or suggestions would be greatly appreciated.
Using a Microsoft SQL Database.
Edit: There are multiple locations that will be stored in the table. I will add a WHERE Location = XXX clause once I get it working and add more locations to the table. Currently there is only one location, so no WHERE clause.
I am using time datatype instead of datetime as I do not want a y/m/d attached to the open/close times.

Answer 1

You need to generate your time stamp using time() so you can get the unix timestamp and then convert it as you wish, this way you'll be able to do time addition and add seconds straight to the given unix timestamp.
Ressource : http://fr.php.net/time
Edit : Just so we're clear and to explain it further : UNIX timestamp is the number of seconds since the 1st of january 1970, so echo time(); will return 1390934768, you just need to process it from there as the docs shows.
This code whille return this as an array : 8
8.5
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<?php
//Function returning unix time from simple time stamp (8 or 17.5 or whatever)
function ttounix($t) {
$tunix = $t * 60 * 60;
return $tunix;
}
//Function returning simple timestamp from unix timestamp
function unixtot($u) {
$tt = $u / 60 / 60;
return $tt;
}
$gap = 30 * 60; //gap in seconds
$t1 = 8; //opening time from db
$t2 = 19; //closing time from db
//setting vars
$n = 0;
$count = array();
//Getting processed time stamps into vars
$o = ttounix($t1);
$c = ttounix($t2);
//Populating the array
while ( $o <= $c ) {
$count[$n] = $o;
$o += $gap;
$n++;
}
//Output
foreach ($count as $output) {
echo unixtot(intval($output)) . '<br />';
}
?>