Following Fabrikam Day back on the 12th April this year, Microsoft are winding the date forward 10 years
This was announced by Pam Misialek on the Inside Microsoft Dynamics GP blog, in a post with a more theatrical title than this post of mine: Hey, where is the #GP2018 sample data? 4/12/2017 isn't working!.
The Fabrikam date has been wound forward once before, back in 2007, but I that was the year I was moving from being a support analyst to being a consultant so I only really started using the sample company after the change of date. It therefore had little impact on me.
However, over the last 10 years, typing 120417 has very much become a habit and I think this change is going to hurt quite a bit.