Revelers at the St. Patrick's Day parade in New York March 17, 2014. REUTERS/Shannon Stapleton

While St. Patrick’s Day is celebrated worldwide every year on March 17, green-clad revelers across the United States might not necessarily be partaking in the festivities at the same time, as different cities’ celebrations fall on varying days, especially during years when the holiday falls on a weekday. With St. Patrick’s falling on a Tuesday this year, some cities have chosen to celebrate a couple of days early, on the weekend leading up to the big day.

New York City’s famous St. Patrick’s Day parade is always held on March 17, unless the holiday falls on a Sunday, in which case the parade is held the day before. Other cities, on the other hand, have their own traditions around the parade. Below is a list of the dates and times for St. Patrick’s Day celebrations in major U.S. cities:

Boston: Sunday, March 15, 2015 at 1 p.m.

Chicago: Saturday, March 14, 2015 at 12 p.m.

New York: Tuesday, March 17, 2015 at 11 a.m.

Philadelphia: Sunday, March 15, 2015 at 12 p.m.

San Francisco: Saturday, March 14, 2015 at 11 a.m.

The holiday may have its roots in the religious feast of Saint Patrick, Ireland’s patron saint, however it has since evolved into a secular festival in the U.S. where it has come to represent a celebration of Irish culture and history. Typically, areas with large Irish communities have staged the most extensive St. Patrick’s celebrations and cities like Boston and New York have centuries-old parade traditions that even predate the founding of the U.S.

Besides the ubiquitous sight of green clothing and shamrocks, St. Patrick’s Day is also characterized by a number of other traditions, including the cooking of corned beef and cabbage. While the dish is considered a traditional Irish meal, it is actually more American than Irish, having been popularized by impoverished Irish-American immigrants. Some cities also have their own unique traditions around the holiday, such as Chicago’s practice of dying its river green, which goes back to 1962.