Drupal view filter by date
I just tried such a Views configuration:


Nodes with a Date field, with multiple dates
Some nodes have dates only in the past, some only in the future, some in both.
Configured a Views page with a simple date filter, when value is greater than now


Views filters:



And Views filters with end-date also works:



End result:



It seems to work out of the box, with the simplest setting for me.
Regarding the delta, this is simply an index number for the value in a multiple value field, its position in the list.