Earlier quoted context omitted.
Can you elaborate what is the cert issue that causing the service down? It's always good to learn from temporary failure.
Today, February 29th, is a "leap day" which happens every 4 years in a "leap year"... Otherwise, the last day of February is the 28th, and today would normally be March 1st. I'm assuming that when the day rolled over, it caused an issue with an internal system at Microsoft, that had something to do with certificate dates and/or timestamps. It's not just Microsoft that it's happening to, today I could not automaticall…
Also whether or not a year is a leap year is easy to calculate:
Year divisible by 4? => leap year; year also divisible by 100? => not a leap year unless year also divisible by 400