The first 節気 “sekki” division of the traditional Japanese calendar is:
the beginning of spring
The second of the three “kō” microseasons within this division is:
“kōō kenkan su”
Bush warblers start singing in the mountains
That makes 黄鶯睍睆 the second microseason of the year!
It typically lasts 9~13 February.
This is #2 in a regular subseries of 365 Days of Japanese, where every five or six days I post about a Japanese microseason that has begun around the same date as the entry. I am taking all information from the list in this article. There is an alternative list here which divides the year into 36 microseasons, and may be more authentically Japanese (rather than being based primarily on Chinese sources). I will use that one next year!
Image credit: Chosun Media.