Ever wanted to know the current date in Microsoft Exchange era? Now you can!
Self-hosted instances of Microsoft Exchange had a problem in their malware scanner, regarding parsing of dates.
Dates were stored as a signed int32, formatted in yymmddHHMM - since the biggest value of 32bit integers is 2147483647, this parsing would fail for any date of year 2022, resulting in an integer overflow, a malfunctioning malware scanner and therefor e-mails not being sent or received.
Microsoft "fixed" this issue in a quick-fix by altering the date format in a way, where January the 1st of 2022 is written as December 33rd of 2021.