UB 19 then TG 309 at Bangkok
Yangon → Bangkok → Kathmandu
Timetable, Bangkok time
08:35UB 19 from Yangon at the gate
21:15TG 309 to Kathmandu leaves the gate
12 h 40 apart on the timetable
TG 309 leaves 12 h 40 after UB 19 arrives on the timetable: more than half a day, so not a connection we count.