Turkmenistan operates 4x a week, with different times. They've all operated lately with the B738 as opposed to the more usual B752, info below and the most recent date they operated.
T5 429/430 - Sundays (17/2)
T5 411/412 - Mondays (18/2)
T5 421/422 - Wednesdays (20/2)
T5 425/426 - Fridays (22/2)
Cheers
Tom