JSFiddle - React, Tailwind, and code Playground

HTML

<form action="http://localhost/mobi2go/trunk/console-x/location/1/settings/hours" class="hours_form" method="post" accept-charset="utf-8">
<fieldset class="show-message">
    <label>Accept orders up to closing</label>
    <select name="accept_till_closing" class="shorter">
        <option>Yes</option>
        <option>No</option>
    </select>
    <div class="input-message">
    </div>
</fieldset>
    <h3>Pick Up Opening Hours</h3>
            <fieldset>
            <label>Sunday</label>
            <div class="opening-hour">
                <select name="pickup_sunday_open_hour" class="opening hour">
<option value="12" selected="selected">12</option>
<option value="01">01</option>
<option value="02">02</option>
<option value="03">03</option>
<option value="04">04</option>
<option value="05">05</option>
<option value="06">06</option>
<option value="07">07</option>
<option value="08">08</option>
<option value="09">09</option>
<option value="10">10</option>
<option value="11">11</option>
</select>                :
                <select name="pickup_sunday_open_minute" class="opening minute">
<option value="00" selected="selected">00</option>
<option value="15">15</option>
<option value="30">30</option>
<option value="45">45</option>
</select>                <select name="pickup_sunday_open_meridiem" class="opening am-pm">
<option value="AM" selected="selected">AM</option>
<option value="PM">PM</option>
</select>                &nbsp;&nbsp;to&nbsp;&nbsp;
                <select name="pickup_sunday_close_hour" class="closing hour">
<option value="12" selected="selected">12</option>
<option value="01">01</option>
<option value="02">02</option>
<option value="03">03</option>
<option value="04">04</option>
<option value="05">05</option>
<option value="06">06</option>
<option value="07">07</option>
<option value="08">08</option>
<option value="09">09</option>
<option value="10">10</option>
<option value="11">11</option>
</select>                :
                <select...

JavaScript

$("button").click(function () {
    var arr = [];

    $("fieldset").each(function () {
        var $this = $(this),
            serialized = $this.children("input").serialize(),
            type = $this.children("legend").text();
        
        // Replace the jQuery-serialized content into valid JSON
        serialized = serialized.replace(/([^=]+)=([^&]*)(&)?/g, function ($0, name, val, amp) {
            return '"'+name+'":'+'"'+val+'"' + (amp ? "," : "");
        });
        
        // Add it to the array
        arr.push('{"type":"'+type+'",'+serialized+'}');
    });
    
    // Join the array into a valid JSON string
    var json = "[" + arr.join(",") + "]";
    
    $(this).next().text(json);
});