JSFiddle - React, Tailwind, and code Playground
by electronoob
HTML
<form>
<label>local time as UTC</label><br/>
<input type="text" value="" id="full"/>
<br/>
<label>utc offset</label><br/>
<input type="text" value="" id="offset"/>
<br/>
<label>timezone</label><br/>
<input type="text" value="" id="timezone"/>
<br/><br/>
<input type="submit" value="send to esp"/>
</form>
JavaScript
offset.value = new Date().getTimezoneOffset();
timezone.value = Intl.DateTimeFormat().resolvedOptions().timeZone;
full.value = new Date().toUTCString();