We tried to reach the Redmond Giant for the specific Timeline and are awaiting a response from the company. The company had earlier confirmed that the service for Windows Phone 8/8.1 and Windows RT will stop working for these platforms in early 2017 but there is no specific timeline which has been given by the company as yet. The closure of these older versions of Skype is likely a part of Skype’s transition to the cloud which has also caused the company to end support for Windows Phone 8/8.1 and Windows RT. The latest version for Skype were released in the month of February by the company. To continue using the Skype app on Windows and Mac you would need to have the latest versions higher than 7.16 and 7.18 respectively. The versions which will not be working from 1st March are 7.16 for Windows which was released in December 2015 and 7.18 version on Mac.