In a broader sense, "v byalata noshh" can refer to the phenomenon of (common in northern latitudes like St. Petersburg or Scandinavia) where the sun doesn't fully set. In literature and art:

It may remind Bulgarian readers of Fyodor Dostoevsky’s short story White Nights , which explores similar themes of loneliness and fleeting connection.

This is one of the most beloved Bulgarian "evergreens." If you are trying to learn or understand the song, here are the key highlights: