The table that I imported has the column in character format for the date/time (MM/DD/YYYY H:MM:SS.XXX) entries. I will like to summurize by minutes instead of seconds. I also try and failed to create a new column in order convert to numeric with short day format.
I think you have the right idea with a formula column, but I don't think JMP's date parsing supports fractional seconds. An easy way to remove that is the Words() function. For example: