St. Patrick's Day is the feast day for St. Patrick, the patron saint of Ireland. Irish citizens celebrate the day by attending church to honor the saint who brought Christianity to Ireland in the 5th century. It's celebrated on March 17 annually to honor St. Patrick's death date.

It’s one of the biggest party days of the year when we celebrate Ireland’s patron saint, St. Patrick. And luckily, it looks like Mr. Patrick liked to party because on March 17 people will celebrate by going out to bars and having a drink, or two, or three.

St. Patrick's Day commemorates Irish culture, highlighted in San Francisco by a sprawling parade dating back to the 1850s. Zoom in: The holiday falls on Monday this year, which means the party starts this weekend.