Grand Central Market has been around for 100 years, and Oct. 27 marks the beloved food hall's exact 100th birthday. Luckily for everyone, that lands on a Friday.

GCM's birthday party will have everything, starting with an installation of 13,000 balloons on the Hill Street side. At 10:30 a.m., a birthday cake will be revealed: a 100-layer creation by Valerie Gordon, who runs a stall at the market. It will contain 390 pounds of butter, taste like chocolate and vanilla with strawberry jam and be decorated with whole fruits. And yes, everybody gets a slice.

The party will swing into high gear at 6 p.m., when the live music starts and the vendors start serving old-timey menu items, such as egg creams at McConnell's. Other stalls will offer "100-cent specials." Come in vintage clothes (anything from 1917 on), and you can enter the costume contest at 8 p.m.

Bring an appetite and comfortable shoes.