Create a date/time range input field which can be used as a variable in other cards (for example, filters or formulas). Use the Select separate start and end date parameter setting in the editor to set the start and end date/times to be defined by distinct date/time variables.
For example, if you would like a filter to be based on the start and end time of an event object, you can define separate date/time parameters for each start and end date/times of the event object, then use these date/time parameters to define a time range parameter.