So finally, its the Leap year that brought down the Windows Azure Cloud services. The root cause behind the Windows Azure Outage was found to be a simple Leap day bug. Read more on Windows Azure blog here.
When the GA creates the transfer certificate, it gives it a one year validity range. It uses midnight UST of the current day as the valid-from date and one year from that date as thevalid-to date. The leap day bug is that the GA calculated the valid-to date by simply taking the current date and adding one to its year. That meant that any GA that tried to create a transfer certificate on leap day set a valid-to date of February 29, 2013, an invalid date that caused the certificate creation to fail.
Source : Windows Azure Blog
Isn't it a brighter spot of the whole issue that Microsoft got 4 years to fix the root cause of the issue :-))