Harvard Law School announced last week that it will advance its on-campus recruitment schedule for law firm employers by one month. Recruiters will arrive on campus during the last full week of August before classes begin. The recession has reduced job offers at law firms nationwide, and students said the school’s recruiting schedule — later than many of its competitors — placed them at a disadvantage. Historically, Harvard and Yale began their recruiting cycles later than other law schools because firms reserved spots for graduates. The number of those reserved spots has fallen as the nation slips deeper into recession.