Nexus 5 Android M Release Date
Google hasn't announced a specific Nexus 5 Android M release date. All we have right now is a broad release window.
The company maintains that the Android M release will come in Q3. Q3 spans from July to September. If this holds, it will mean that the Android M release will come less than a year after the Lollipop release. Android 5.0 was released in November.
Google says that the release will come in "later Q3" which means that it probably won't arrive in July or early August. Android M rumors have pointed to a release inside the month of August though that remains unconfirmed. Release dates depend on internal testing and testing often puts up roadblocks. Thus, release dates can move.
With a release probable for August or September, the Android M update will probably arrive in and around the release of Apple's iOS 9 operating system. iOS 9 is confirmed for the fall and it will likely arrive alongside new iPhones.