Reply To: Book direction in epub format for languages from right to left

Are you using InDesign English for creating EPUBs in Arabic or Arabic version of InDesign for the same? In case you are using InDesign Arabic, your book would be generated Right to Left by default.
This can be verified from the generated EPUB. Open your EPUB in Sigil (open source EPUB editor). View the contents of content.opf file.
Look for page-progression direction here, it should be rtl ( should be similar to : <spine page-progression-direction=”rtl” toc=”ncx”>)