Android 6.0 Marshmallow is most probably releasing by the end of September 2015 or early in October. The update will be officially announced alongside the launch of Nexus 5 2015 , which will ship with Marshmallow out of the box.

Soon after that Marshmallow update will be released to Nexus 6, Nexus 5 2013, Nexus 9, Nexus Player and maybe Nexus 4 as well. But from Samsung and other manufacturers, the update won’t come as quick as Nexus devices will.

For the Samsung Galaxy S6 and S6 edge particularly, Marshmallow update will arrive anytime between 30-45 days of official release by Google.

We’re basing our assumption on Samsung’s release schedule for last year’s Android 5.0 Lollipop update. Samsung pushed out the first Lollipop build to its then Flagship Galaxy S5 within 30-45 days of its official release on Nov 3, 2014.

So based on that, either of the Galaxy S6 or S6 edge should get Marshmallow update within that period, and we’d be pretty happy if Samsung does deliver the update that quick.

However, as far as carrier locked S6 and S6 edge variants are considered, we don’t think the Marshmallow update will arrive anytime before 45 days. Give or take, carriers will take at-least 45-60 days to release the update to their specific variants. Let’s discuss a carrier-wise breakdown of Marshmallow update:

T-Mobile S6 and S6 Edge Marshmallow Update

Model numbers: G920T (S6) and G925T (S6 edge)

Of all the carriers in USA, we expect T-Mobile to bring the Marshmallow update first to S6 and S6 edge variants first. We’ve seen T-Mobile pushing out the 5.1.1 update to the said devices well before any other carrier, so it’s a sensible guess to T-Mobile S6 and S6 edge will receive Marshmallow update before any other Samsung devices in the USA.

Expected release date: 45-60 days of Google’s release.

Sprint S6 and S6 Edge Marshmallow Update

Model numbers: G920P (S6) and G925P (S6 edge)

The Sprint S6 and S6 edge should receive the Marshmallow update anytime after T-Mobile does, because that’s how we’ve seen the pattern to be for various 5.1.1 updates to the device in 2015.

Expected release date: 45-60 days of Google’s release.

AT&T S6 and S6 Edge Marshmallow Update

Model numbers: G920A (S6) and G925A (S6 edge)

It’s hard to guess AT&T’s Marshmallow update timelines. While the carrier is usually slow at pushing major Android updates, but there have been times when it has really outshined all other carriers. Still, for a major release like Marshmallow, we’d say AT&T will take time to deliver.

Expected release date: 45-90 days of Google’s release.

Verizon S6 and S6 Edge Marshmallow Update

Model numbers: G920V (S6) and G925V (S6 edge)

Aha! Need we say anything for the Verizon or you already know about the its consistently poor record of slow rollout of Android updates. Please, just don’t expect much if you’re Verizon. Keep your calm if you’re delayed even by full 90 days to get Marshmallow update on your Verizon S6 and S6 Edge.

Expected release date: 60-90 days of Google’s release.

So that was all for the Galaxy S6 and S6 edge Marshmallow update release date for the major carriers in USA. As for other carriers, we guess it’ll around the same time as major carrier rollout the update (upto 90 days).

This is just our assumptions for the Marshmallow update release dates for S6 and S6 edge, if you’ve anything to add to this article, please feel free to post about it in the comments section below.