Two Waltham Post Offices will host "Passport Day" Saturday, during which customers can apply for passports or make inquiries on them, according to the U.S. Postal Service. 

The event starts at 8 a.m. and runs to 11 a.m. at the Main Street and Lexington Street post offices.

Passport applicants should bring the following information: an unsigned passport application, photo identification, a photocopy of that identification and documentation proving you are a U.S. citizen. Applicants under 16 must have parents with them.

Photo services will be available. Also, be prepared to pay the application fee.