Microsoft's support for Windows Phone 8 and Windows Phone 7.8 will end in the second half of 2014, according to the software maker.

Microsoft listed the sunset dates on its Web site recently, with WP8 support ending July 8, 2014, and WP7.8 support ending Sept. 9, 2014.

Both dates are 18 months after the support lifecycle starting date. The updates provide changes and improvements to the OS, including security, that are distributed by either the wireless operator or the phone manufacturer, Microsoft said.

The support lifecycle for Windows RT, which runs on tablets from various manufacturers, has not been detailed, although Microsoft said last fall that the policy "will be communicated as available." As of Monday, that policy remained in place for Windows RT on the Microsoft site.

Last November, Microsoft said its support of Surface RT tablets (also running Windows RT) would expire April 11, 2017. That time frame is less than half the usual 10 years of support that Microsoft gives its software products. For its Windows Phones, the time frame is less than one-fifth as long.

Computerworld