This not a case of what annoys me, rather one of what confuses me. In the Beta and RC releases of the OS (such as Windows 8 Developer Preview (W8DP), which I'm running now), there is an expiry date that gives the date when the evaluation period for the OS finishes. Currently for W8DP, this is 11/03/2012. Does this mean 11th March or 3rd November? It would be far less confusing if they chose the 13th as the earliest day of the month for this sort of thing.