Looks like I messed up and all the bus tickets from Chiang Mai to Mae Sai are sold out for this friday. Luckily I still got till saturday until my visa expires.
Can anybody tell me if the borders are also open on saturdays?
TLDR : Answer Summary
The conversation discusses the availability of transportation from Chiang Mai to Mae Sai with an emphasis on the border crossing schedule. Several comments confirm that the Mae Sai border is open every day, and there are various travel options available, including local buses and border run companies.