Apple previously announced that its next-generation OS X operating system, called Mountain Lion, would launch sometime in July, although a specific date was never announced. According to a report from 9To5Mac, the Cupertino-based company’s retail stores in both the United States and overseas are planning overnight updates on July 24th — the same day Apple will announce its third-quarter earnings — that could include the posting of marketing material and OS installations on store computers. The iPhone-maker previously announced OS X Lion availability during its earnings call last year. Along with other improvements, OS X Mountain Lion includes Notification Center, Dictation, Gatekeeper and Apple’s Reminders and Messages apps. Apple’s latest operating system will be available for download in the Mac App Store for $19.99. Read the full story at Boy Genius Report.