According to an updated software release schedule from Canada’s second largest mobile provider, Telus, Android 6.0 Marshmallow will begin rolling out to the Nexus 5 and Nexus 6 on Monday, October 5.
While the company notes that dates are subject to change, the date makes sense in the scheme of how Google typically distributes new versions of Android to older devices shortly after the announcement and release of their new Nexus flagships.
This year, we know that the LG Nexus 5X and Huawei Nexus 6P will almost certainly be announced on September 29, with a release either that day or shortly thereafter. In previous years, Google announced the release schedule for older Nexus devices at the same time.
Last year, the Nexus 6 was announced on October 15, making it available to purchase two weeks later, October 29. Deliveries began arriving mid-November, right around the time Lollipop began hitting other Nexus devices. The Nexus 5 Lollipop update, for example, began rolling out on November 12.
This year, it appears that Google may have a head start on both the release of its new smartphones, and the rollout of its latest version of Android, Marshmallow. That may be because Marshmallow is more of a stability and performance improvement update, with only a handful of show-stopping features.
Update – September 25th: Perhaps Telus jumped the gun as the listing for Android M update for the Nexus 5 and Nexus 6 has been removed from their chart. Hopefully this date still sticks.