If the date parameter includes time information, then function does not return it. However, if date includes invalid time information (e.g. "89:98"), then an error occurs.
If the date parameter is a string that includes only numbers separated by valid date separators, then function recognizes the order for year, month and day according to the short date format you specified for your system. Function also recognizes unambiguous dates that contain month names, either in long or abbreviated form. For example, in addition to recognizing 12/30/2021 and 12/30/21, function also recognizes December 30, 2021 and Dec 30, 2021.
If the year part is omitted in the date parameter, then function uses the current year from your computer's system date.
d = DateValue(date)