Sahasra Chandra Darshana is celebrated by Hindu Brahmins as SADABHISHEKAM. It is generally celebrated on completion of 80 years of the husband. The unique significance is that there will be more than 1000 Purnima days by that time.
Seeing 1000 Full Moons in one's life is considered as great and it is believed that he will definitely attain Moksha by the blessings of Lord Chandra. On the occasion of completion of 80 years or any time afterwords, a ceremony called Sahasra Chandra Darshana Vratham could be performed by the living couple with rituals like Mritunjya Homa, Bheeshma Ratha Santhi, Rudra Ekadasa Homa and Udakasanthi. Taking blessing from the couple who perform "Sahasra Chandra Darshana Vratham" is considered very much worthy and they are blessed for long life.