Hey @Valley_Gurl,
Luckily, this is easier than it looks. 12:00:00 AM January 1, 1904 is the baseline value for date/time values in JMP. If you have date only values (first column), underlying the presented formatted value is a numeric value that is the number of seconds elapsed the baseline time in 1904 to midnight of the given date value. If you have a time only value (your second column), it is the number of elapsed seconds since midnight (on January 1, 1904 if you convert it to date/time). Therefore, all you need to do is sum them together, and then apply a format.
The column formula for data/time:
Applying the format:
*Make sure the input format is "Numeric" since the result of the sum will just be a large integer representing the number of seconds from baseline to the desired date/time value.
Result:
-- Cameron Willden