The quote you posted on your reply, from my OP, was a copy paste from the UK Thai Embassy website, I was just showing conflicting number of days on the UK Gov website and The Thai Embassy website, it's nothing to do with me, I am going for 4-5 weeks, thanks for the reply though.
https://london.thaiembassy.org/en/page/84498-faq?menu=5d6636ce15e39c3bd0007350