I have a question, are there any manga/manhwa similar to 19-days?

tamen de gushi, but its a light GL instead of BL.

http://www.mangago.zone/read-manga/nan_hao_shang_feng/
Not bl just a comedy slice of life series with the same vibes as 19 days

http://www.mangago.zone/home/mangalist/717570/

Kinda same vibes http://www.mangago.zone/read-manga/18_unlimited/

Oh I remember this one I think I read it, but thank you so much(⌒▽⌒)

That is totally fine, thank you so muchლ(´ڡ`ლ)

Thank you (=・ω・=)