Windows 10 Mobile is almost here, according to the grapevine. A leaked document shows that Microsoft will roll out the long-awaited software on March 17.

However, China-based website ITHome, the source of the leak, claims that the mobile operating system's rollout was supposed to be announced March 14.

The day has come and gone but the much-awaited Windows 10 Mobile over-the-air release has yet to be made official by the Redmond-based software giant.

However, Windows users still hope that the software will come knocking on Windows phones on the March 17, as the leak suggests. After all, Microsoft promised an "early 2016" rollout.

Also, the leaked document contained the devices that could very well be the first bunch of Windows 10 Mobile recipients. These handsets include the Lumia 535, 636, 638, 640, 640 XL, 830, 930 and 1520.

The same Windows devices have always been expected to be the first devices to get Windows 10 Mobile. However, it is best to take this report with a grain of salt, especially after the first part of the claims involving the March 14 announcement did not transpire.

Windows 10 Mobile was originally slated for a December 2015 release. After Microsoft failed to keep its word, it promised to push the update early this year, shying away from announcing a specific timeframe.

Rumors then abounded about the software supposed to be released in January, only to be delayed again to February. Microsoft has kept its lips tight in the midst of these reports.

The company will be releasing Windows 10 Mobile to a majority of its smartphones, although Windows phones with 512MB won't be able to enjoy all the features it has to offer.

Meanwhile, the latest internal builds of the mobile operating system allow handsets to make Microsoft's mobile digital assistant Cortana as the default SMS app.

Not much is known about the purpose of the feature and it does not look like it is operational at this time. For now, users will have to settle for having Cortana read and send text messages.