basanta panchami | बसंत पंचमी

The fifth day after the full moon in the month of January or February marking the beginning of the spring season and the Holi celebrations in Braja, which go on for roughly one month, till the next full moon (holi). The basanta or spring season is particularly associated with the amorous sentiment and the eternal raas of Vrindavan.

Reference: Prema Rasa Madira - The Intoxicating Bliss of Divine Love, Vol. 1, Ch. 3