blooming date; day of flowering
Used especially in contexts like cherry blossom forecasts or botanical records to indicate the date when flowers open.
今年の桜の開花日は平年より早い。
This year's cherry blossom blooming date is earlier than average.
Compound of 開花 (kaika, 'flowering') and 日 (hi, 'day'), with rendaku voicing of ひ to び.