Shiva Purana
फाल्गुने चोत्तरान्ते वै प्रारभेत महोत्सवम् ॥ चैत्रे चित्रापौर्णमास्यां दोलां कुर्याद्यथाविधि ॥ ७ ॥
In the month of Feb-March in the star Uttarā-Phālgunī he shall start the great festival. In the month of March-April on the full-moon day and Citrā star, he shall perform the Swing-festival duly.
english translation
phAlgune cottarAnte vai prArabheta mahotsavam ॥ caitre citrApaurNamAsyAM dolAM kuryAdyathAvidhi ॥ 7 ॥
hk transliteration by Sanscript