In Forum: Apple Operating Systems
By User: iphonehack3r
OS X 10.8 was announced on February 16 2012 and released on July 25 that year
Mac OS X 10.7 however, was announced in June and released a month later
So if Apple follows this pattern 10.9 should be released in July and most likely announced in June, but the patterns Apple have been running by have been disrupted recently, the yearly iPad release was changed to 6 months and the iPad Mini was released a month after the iPhone 5.
By User: iphonehack3r
OS X 10.8 was announced on February 16 2012 and released on July 25 that year
Mac OS X 10.7 however, was announced in June and released a month later
So if Apple follows this pattern 10.9 should be released in July and most likely announced in June, but the patterns Apple have been running by have been disrupted recently, the yearly iPad release was changed to 6 months and the iPad Mini was released a month after the iPhone 5.