It's a bit confusing for the admins when a sales discount that is deactivated by the End Date still displays as active.
I know it does not apply the discount if the current date is after the End Date of the discount but it is still confusing.
Maybe you can add a daily verification that will mark them as inactive.
Also, a way to filter/search the active discounts would be very nice. Some customers are hoarders of sales discounts. They never delete anything.
And since we are at this point, a segmentation based on permissions/shop/area would be very helpful for solutions with a lot of webshops. Otherwise the guy in China will also have to deal with the sales discounts of the guy in Netherlands and so on.