I had an appointment at the NEN, the Dutch standards organisation. That did not go as planned. I received a message indicating that the meeting was cancelled.
At the time of the meeting, I received a telephone call where I was... It turned out that my Google calendar and their Lotus Notes did not talk properly. We made a new appointment.
When I arrived at the NEN office, the receptionist told me "we expected you two hours earlier". Again, I was bitten by the incompatibility between two calendar systems. I may not have researched if there is an applicable standard but I definitely feel the need.