Does opening an .xlsx file in systems with different locales correctly render the content according to locale, regardless of what locale file was originally created in?
e.g. User 1 creates excel file (XLSX) in en-US as "2/7/2019" (Feb 7th 2019) e.g. User 2 opens this in en-GB locale in Excel application - will he see this content correctly rendered as "7/2/2019" (Feb 7th 2019) according to British convention?
Similarly for time, number formats
If the field is formatted as 'Date' or 'Time' using the default Category, then the dates should appear as their local notation if you use the asterisk notations. You could of course use 'Custom' Category and set dd/mm/yyyy, but by the sounds of things you want your US users to see mm/dd and your UK users to see dd/mm.
Source: https://support.office.com/en-us/article/format-a-date-the-way-you-want-8e10019e-d5d8-47a1-ba95-db95123d273e and refer this image, specifically the comment at the bottom of the dialog.
