My question is similar to Google Docs date in “dd/MM/yy” format and How can I change the input format for dates in Google Docs' spreadsheet?
BUT
unlike those answers, I'm trying to get the format with years first, which is non-ambiguous, more tech friendly and can be sorted alphabetically. I'm not aware of any locale that would put years first ?
Also, is it possible to automatically convert dates that would be typed with dd/mm/yyyy to yyyy/mm/dd ? (assuming my colleagues locale is indeed dd/mm/yyyy and NOT mm/dd/yyyy