Often, where there is one comma, there should be a second. When commas are given the task to set off an element within a sentence they work with a partner. One comma waves the starting flag, indicating the begin of the off-set element. The second comma waves the checkered flag, signaling the end of the off-set.
Dates and locations are generally double-teamed by commas.
Tuesday, March 21, is the first day of spring.
The restaurant scene in New York, New York, is vibrant.
As with every rule, there is an exception. If an off-set comma is used within the title of a work and, but the work itself is not off-set by commas because it functions as an sentence component, the second comma may take a holiday.
Sarah, Plain and Tall is the title of a book.