My dear devotees,

We want to observe Purusottama month and the month begins on pratipat. In some places, pratipat is on the 16th. Gaudiya Matha does sankalpa on amavasya so that seems alright. Bhaktivinoda Thakura describes the end of Purusottama month; normally it ends on the krishnapaksha caturdasi.

Your well wisher always,
Jayapataka Swami
14 May, 2018