A Time Step Interval is required.
Specify a Time Step Interval to define the temporal extent of each time slice.
The number of seconds, minutes, hours, days, weeks, or years that will represent a single time step. Examples of valid entries for this parameter are 1 Weeks, 13 Days, or 1 Months.
If Temporal Aggregation is checked off, you are not aggregating temporally and this should be set to the existing temporal structure of your data.
If Temporal Aggregation is checked on, you are aggregating temporally and this will be the Time Step Interval you would like to create. All features within the same Time Step Interval will be aggregated.