Microsoft blames Azure cloud computing outage on leap year

The outage on Microsoft's Windows Azure cloud computing platform that caused the government's G-Cloud service to go offline was the result of a calculation error caused by the extra day in February due to the leap year.

Writing on the Azure blog the firm's corporate vice president for service and cloud, Bill Laing, said while the firm had still to fully determine the cause of the issue, the extra date in the month appeared the most likely cause.

"Windows Azure operations became aware of an issue impacting the compute service in a number of regions. The issue was quickly triaged and it was determined to be caused by a software bug," he said.

"While final root cause analysis is in progress, this issue appears to be due to a time calculation that was incorrect for the leap year."

Laing added that the firm was confident it had now fixed the issue although noted that some customers may still be experiencing issues with their services.

"Some sub-regions and customers are still experiencing issues and as a result of these issues they may be experiencing a loss of application functionality. We are actively working to address these remaining issues," he added.

The outage affected customers across the globe, with the G-Cloud service from the government one of the most high-profile accounts to be affected, as it was only launched last week as part of Whitehall's attempt to improve the use of IT services in the public sector.