DEALING WITH START AND END DATES

Set up a date table, marked as a date table. There's plenty of videos and articles about how to do that.

Don't create any relationships from the date table to your fact table.

Create a measure like

Account is visible =
VAR MaxDate =
    MAX ( 'Date'[Date] )
VAR StartDate =
    SELECTEDVALUE ( 'Table'[Start date] )
VAR EndDate =
    SELECTEDVALUE ( 'Table'[End date] )
VAR Result =
    IF ( StartDate <= MaxDate && ( ISBLANK ( EndDate ) || EndDate >= MaxDate ), 1 )
RETURN
    Result

Add this as a filter to a table / matrix visual and it will show those accounts active on the selected date. Use columns from the date table in the slicer.

wemsomba10 

I think you could also try this. Similar to what Johnt75 said, create a Calendar table. Dont relate the tables.

The difference in this approach is that we create a measure that explicitly shows whether the account is "Active" or "Inactive".

1. In your data table, replace nulls in the End date with 31/12/9999. (You mentioned nulls in your End date, so use this to resolve that)

2. Add a filter on the Date field from the Calendar table. (the drop down in the snapshot below)

3. Write this measure and add to your table visual.

4. if you only want your output table to show Actives...then filter the table on Account Status "is Active"

The date filter could become cumbersome if you have a huge date range, but just another idea for you.