Super Junior's Ryeowook will be dropping a surprise solo song later this week.

The song, titled "Calendar", is a ballad that has a dream pop sound and a dreamy guitar riff. The song tells the story of flipping through the calendar and realizing that every day is special. The song is by producer Park Won Jun. It is arranged and composed by B.BTAN and LiO, with lyrics by Cho Sung Tae, Han Soo Min, Kim Judy, and CLEF CREW.

The song will be released at noon KST on October 16th.