For those who pay attention to such things, the pithy Thai way to say "Friday the 13th" is ศุกร์สิบสาม /suk sip saam/ (alliteration, you see). Of course, วันศุกร์ที่สิบสาม /wan suk thii sip saam/ also works, but it's not as catchy.
In the U.S. there's a new Jason movie out today, of course. Here it's not such a big deal -- คนไทยไม่ถือ.
(For me, it's just my 26th birthday. Happy birthday, old man.)