1. input
For input to be properly seen as you type (meaning RTL)
for chrome right click and on the context menu choose Writing direction
for firefox just press Ctrl-Shift-x to toggle between LTR and RTL
2. output
For output you need to add <div dir="rtl"> before and <div> at the end of you RTL input
sort of like this
<div dir="rtl">
يوم جيد
</div>
which will give you this
يوم جيد