Microsoft had originally planned to begin rolling out Windows 10 Mobile to its Windows Phone 8.1 devices at the end of last year, but in December, it revealed that owners of those handsets would have to wait until "early next year".
Several of Microsoft's carrier partners were apparently under the impression that it would begin upgrading devices last month, but reports of a further delay until February proved to be correct. However, there have still been no official announcements about the rollout - although as WinPhoneMetro spotted, one part of the company apparently revealed its upcoming release date earlier this week.
On its Facebook page, Microsoft Mexico told customers on Monday that the update will be available from February 29, also reminding them that not all devices will be able to upgrade to Windows 10 Mobile. Microsoft confirmed to Neowin last year that ten of its Windows Phone 8.1 handsets would initially be eligible for the upgrade.
Incidentally, back in September, photos taken at a Microsoft Mexico event prematurely confirmed many of the details about the Lumia 950 and 950 XL, the company's latest Windows 10 Mobile flagships, two weeks before they were due to be announced.