Now that Google has made the rollout of Android 6.0 (also known as Android M or Marshmallow) official, bringing it to their own Nexus devices first, it is only a matter of time before it slowly trickles down to other Android devices. Take Sony, for example, as they have provided their consumers with the Xperia series which includes three variations of the Z5, the Z4 tablet, and several versions of the Z3 series. This is what is known on the Android 6.0 M or Marshmallow Release Date for the Sony Xperia Z5, Z4, and Z3 series from carriers like Verizon, AT&T, Sprint, and T-Mobile.
A list form Neurogadget shows that the Sony Xperia devices scheduled to receive the Android 6.0 upgrade include the Xperia Z5, Xperia Z5 Compact, Xperia Z5 Premium, Xperia Z4 Tablet, Xperia Z3+, Xperia Z3, Xperia Z3 Compact, Xperia Z3 Tablet Compact, Xperia Z2, Xperia Z2 Tablet, Xperia M5, Xperia M4 Aqua, Xperia C4 and Xperia C4 Ultra.
According to International Business Times, the rollout of Marshmallow for Xperia devices was scheduled to begin before the end of the year. As rollouts for Android go, the rule is that the newest Android devices are the first to receive it. This would make the first to receive it will be the flagship Xperia Z5, as well as its variations of the Xperia Z5 Compact and Xperia Z5 Premium, possibly as early as before the end of this year.
In fact, it looks like Sony started the build of the Marshmallow update for the Z5 series last October, which means that Z5 users could be in for their update in November and December, according to Xperia Sony. The release date would also be dependent on the carrier, which in the United States would be the big guys like Verizon, T-Mobile, Sprint, and AT&T.
From there, it would, of course, spill out the Z4 Tablet, as Sony didn't have a Z4 smartphone for this year. This would make the next in line to receive the Marshmallow upgrade the Xperia Z3 and Z3 Compact devices, which were last year's flagship model. A recent report from Sony Mobile Blog has stated that a test build of the newest version of Android has reached the Z3 series, but this only targets "an elite group of users". This upgrade should reach Xperia handsets shortly.
Of course, the probably with upgrades is it soon becomes a waiting game to Android users, even the ones with a relatively new Android device less than a year old could be waiting until 2016 to receive their upgrade. Tech Radar has stated that Sony has been known to do their upgrades slowly, so it might be a bit of a wait.