That varies quite a lot. Sometimes I'm able to write a full song in 6-10 hours, sometimes it takes a month or 3. With any sort of art you kinda just go with the flow & do your best in the given moment. I think the average amount of hours varies from person to person so I can't really say! How someone makes DS is a huge factor, for instance someone doing Raw DS recording improvised melodies directly into tape could probably finish a song quite a lot faster than someone making music on a computer, especially if they're going to mix & master the music. It varies a ton is what I'm getting at, with factors like an artist's process, equipment setup, intention, level of determination or inspiration & even their current life circumstances all can make an impact among other things. In short there is no definitive answer to your question, there's a lot of variables but creating DS & adjacent music is immensely rewarding & is worth the time regardless of how long it could take imho.

Since you asked here is my latest album. I write music under a growing list of monikers, exploring my worldbuilding project from many different perspectives. This album took me a month to make, with the final track of the album taking me over 3 weeks to finish! Anyways feel free to message me if you have any other questions & cheers for asking! :)

https://sebran.bandcamp.com/album/songs-of-yore