Trying to organize my thoughts on how to save multiple, time worked entries into db.

So my thoughts on how to approach this are as follows :

create 2 form fields ,

```
<select value="<?php echo $beg_time; ?>" name="beginningtime" id="beginningtime">
     <option value = "8">8am</option>
     <option value = "etcetc">etcetc</option>
     <option value = "6">6pm</option>
</select>
<select value="<?php echo $end_time; ?>" name="endtime" id="endtime">
     <option value = "8">8am</option>
     <option value = "etcetc">etcetc</option>
     <option value = "6">6pm</option>
</select>
// Third input to have time worked that I want to save
<?php $end_time - $start_time = $hours_worked;?>// replace with jquery to update on client side
<input type="hidden" value="jQueryhours_worked">

//Server Code :
//somehow concatenate $hours_worked, so that saved value may look like this :
//2,3,5,1

```

Is there an easier way of doing this, am I reinventing the wheel?