Split your DateTime column into a separate date & time columns in fact table, so that you can join the date to the date table & the time to the time table. The time need to be converted to the nearest round minute or second so that every time in your data corresponds to a row in your time table.
Reference:
https://intellipaat.com/community/6461/how-to-include-time-in-date-hierarchy-in-power-bi