Uma Maheshwara puja is for long and happy married life. Uma (Goddesss Parvati the consort of Lord Shiva) and Lord Shiva puja is perfomed as they are considered to be the perfect match i.e. Shiv and Shakti. This puja is considered to be best for marital happiness. If there is any discord in the relationship, all are resolved.
Once a year one shall conduct this puja for a happy married life. Lord Shiva is the Lord of mercy and compassion. He protects devotees from evil forces such as lust, greed, and anger. He grants boons, bestows grace and awakens wisdom in his devotees.
In todays world, where both husband and wife are working and sometimes some discord develops between couples. To remove discord or malefic effects of planets on husband and wife, Uma Maheshwara Puja is recommended for long and happy married life.