Translation? (possibly bosnian)

I came across a scrap of paper on of our co-workers discarded. On it was…I think:
SVE OSIM PON I SUB V TETIRI

Anyone understand this…message?

I don’t speak bosnian, but with my limited knowledge of slavic languages, it looks like some kind of note regarding days of week. “PON I SUB” almost for sure translates as “mon(day) and sat(urday)”. “Sve osim” probably translates as “Anything but” or, in supposed context, “Any day other than”. I’m stumped at TETIRI. Googling returns place in Turkey, but I’m not sure if it even makes sense.

More context maybe?