Airbnb for US culture will show the popup with the 11th of February 2017.
This becomes more entangled when we get Russian, Ukrainian and Kazakstan format DD.MM.YYYY, which is often shortened to DD.MM.YY. For example, the 11th of February 2017 is usually written as 11.02.17.
To make internationalisation more complex some countries (Chine, Lithuania, South Africa) use YYYY-MM-DD or YYYY.MM.DD, which sometimes people like to shorten to YY.MM.DD, and our previous example becomes 17.02.11.
If you think that nothing can be worth, there are countries (Germany, Canada, Sweden, Philippines), which apply different date formats depending on a context.
Taking into the account all previous points and preventing likelihood problems the solution of the problem should be:
1) Visible immediately as a static text without any data manipulation (no need to open a popup date editor)
2) A day, a month and a year should be distinguishable from each other
3) The distinguish signs should have the colour of the text and be readable after a monochrome print, e.g. in books and newspapers.
4) The distinguish signs should be simple and built from UTF symbols.
Proposal of a solution
Let us start our visual identification from the shortest amount of time - a day, to the most lasting - a year. The simplest visual effect, that is also very convenient to program or use in draw editors, is underlining. Underlining also works good with all popular charset encodings.
A day gets full width underline = DD;
A month gets a half width underline if the year part is short (YY) = MM; otherwise month has no underline = MM;
A year has no underline = YYYY or YY;
Our initial confusing date presentation now becomes absolutely clear:
Some people like to trim zeros and write, for example, 7.9.2017. Even this date can be transformed to an obvious presentation: 7.9.2017.
More complex 11.10.12 YY.MM.DD can be transformed to 11.10.12 or to 12.10.11, which is actually the same as 12.10.2012 and 10/12/2012.
And now the bonus for developers and almost anybody who process much data. A common SQL result nowadays says nothing about a date format:
while after our small fix the data is a pleasure to read:
Table of different date formats
|2/11/2017||The 11th of February 2017|
|2/11/2017||The 2nd of November 2017|
|10/3 or 10/03||The 10th of March|
|2017-12-10||The 10th of December 2017|
|05/04/03||The 5th of March 2003|
|05/04/03||The 3rd of March 2005|
|2/3/2020||The 3rd of February 2020|