December 17th marks the 10th day of the lunar calendar when the male energy of skillful means is most prevalent.
This day is also the anniversary of Guru Dorje Drollo, one of Guru Rinpoche's manifestations. On the 10th day of the month of the Tiger, Guru Rinpoche conjured his wrathful form at Paro Taktsang in Bhutan and subdued all the local deities and treasure guardians. He then made them the protectors of the Terma teachings (hidden treasures) concealed in both central and remote places in teh Himalayas, and entrusted them with the secret oral instructions, to be given in the future to Tertons (treasure discoverers) at suitable times. He became known as Guru Dorje Drollo or Vajrakrodha, the Guru of the Adamantine Wrath.