Checking the ALSA site the bus times are now very different. It looks as though the bus runs in the morning on Saturday, Sunday and Monday; then afternoons Tuesday,Wednesday, Thursday and Friday.
The link is
here for daily times and can be checked for each day, rather than giving a weekly list which I had found previously. It stops at Tineo, Pola de Allande and Berducedo. Not sure if it starts at oviedo or is a change of bus these days.
PS - ignore the 'incorrect petition' at the top of the page - it is because of how I made the link. Entering the details should still work OK.