One of the more frustrating aspects of Boston's neighborhood libraries is that they are seldom open for people who work during the day. While the main library at Copley enjoys evening hours most weekdays, and is open weekends, too, the local "stepchild" branches out in the hinterlands are closed summer weekends and available at night only once a week. Boston's mayor, BPL leadership and the unions each blame one another for the situation but whatever the truth may be, branch library patrons are left out in the cold after work. It doesn't have to be this way, as the executive director of Ohio's Cuyahoga County's Library has demonstrated in her 28 libraries, also unionized. To raise funds for weekend hours, and with help from the Cleveland Foundation, the library's clerical staff agreed to be trained for the system to become a one-stop Passport Acceptance Location, just like the Post Office. Last year, at seven of its locations, libraries were earning between $8,000 and $9,000 a week offering passport services to library patrons. "Our clerical workers embraced the opportunity to take on higher-level opportunities," Sari Feldman, the executive director, said in an interview on WGBH's Diane Rehm Show this summer, adding that the entire clerical staff is now learning to offer passport assistance at all of its 28 neighborhood libraries and that, starting this September, all libraries in Cuyahoga County will reopen on Sundays.