This might sound like an obvious feature, but it turns out that reading the Excel format can be tricky, as Excel doesn't have native date/time data types. Those are stored as floating-point numbers, and only by looking at (and sometimes guessing from) the formatting style for a cell can you really tell that its value contains a date/time. Then the value must be extracted and converted and luckily, there is an algorithm for that. (Oh, and did you know that you cannot represent dates before 1900 in Excel?)
|Excel represents many data types using floating-point numbers|
We hope you will like this feature, which is present in Orbeon Forms 2019.2. See also the documentation.