How hard can it be? It seems to be incomprehensible hard for some to understand the ISO 8601 date format YYYY-MM-DD and acknowledge ISO 8601 as the international standard.
One example; at the company we use Microsoft sharePoint collaborative software. As an american i.e. U.S.A company Microsoft is unaware of ISO standards e.g. date formats are national in sharePoint. The swedish date format in sharePoint is ISO 8601 since we swedes since long have adopted the SI/ISO standard. The US date format is not ISO 8601. The US sharePoint admins at the company are unaware of ISO and do not want to promote the ISO 8601 as default as they believe this is the swedish date format only, instead they use the US date format since they think the US standard is the world standard. If Microsoft could introduce the ISO 8601 as a recognised date format in sharePoint, it would be much easier for me to evangelize the benefits of using one recognised standard format as default for dates in the company. This will probably only happen after the Chinese have established a Chinese hegemony, their date format is sort of big endian in accordance with ISO 8601.