JMP uses a Jan 1, 1904 epoch for time 0 in seconds ( Mac Excel epoch date)
Python uses the standard UNIX Jan 1, 1970 epoch date for time 0 in seconds.
JMP 19 properly marshals date time values across JSL / Python boundaries.
JMP 19 has a dt = jmp.from_dataframe(df) that will create a date table directly from the data frame in memory.
In JMP 18 the only in-memory choice is to build the columns yourself, looping on the pandas columns and paying attention to date/time conversion.
Alternatively, you could go through CSV. That's the way it was done in JMP 14-17. But be aware you can get small binary differences in numerics when going binary -> CSV -> binary. There are samples in JMP 18's SAMPLE_SCRIPTS/Python directory that show how to go the CSV route. Basically, tell pandas to save as csv, then tell JMP to open the CSV.
I really suggest you upgrade to 19. Dramatic improvements to data table handling have been made in 19.