Shishira () is the season of winter in the Hindu calendar. It comprises the months of Magha and Phalguna and corresponds to mid-January to mid-March in the Gregorian calendar.
References
Sources Selby, Martha Ann (translator). The Circle of Six Seasons, Penguin, New Delhi, 2003, Raghavan, V. Ṛtu in Sanskrit literature, Shri Lal Bahadur Shastri Kendriya Sanskrit Vidyapeetha, Delhi, 1972.