The Sony Xperia Z2, Z3, Z4, Z5 were seen listed on Xperia blog to receive the Android 6.0 Marshmallow recently. Although Sony hasn't provided any confirmed schedule of the update yet, it is predicted to happen before the end of the year.

According to International Business Times, the Japanese tech giant has unveiled the list of devices that will get  the firmware update but its schedule is still yet to be announced. Thus, nothing is confirmed as of this moment  and it wouldn't be  a surprise if it will take longer than anticipated.

Nevertheless, it is already confirmed that Sony will release the new Android 6.0 Marshmallow update to over a dozen Sony devices, such as Xperia Z5 and Xperia Z5 Compact.

As stated by Sony, it will make the Android 6.0 Marshmallow available for 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 C5 Ultra, Xperia M4 Aqua and Xperia C4*.

In addition, the company added that they have been working hard to release this major update to as many of their devices as possible and as quickly as they can. They're very excited with regard to the latest Sony features & functionality as well as the improvements they've made to the user experience which they will share more shortly.

Last October 19, the Xperia blog has announced that  the Concept for Android Marshmallow firmware builds for the Sony Xperia Z3 series has already started rolling out. A few fortunate people have already started to get invites but Sony said the Android 6.0 Marshmallow concept firmware will be released gradually "over the coming weeks." In addition, it is said that Sony has released some more spaces for the program, so meaning, a Z3 user could still get a place on the beta.

It is believed that Android 6.0 Marshmallow update could hit the Xperia Z2, Z3, Z4, Z5 Sony mobiles before the end of the year, on the other hand, some of the Sony devices are rumored to receive the update in January 2016.