The DataDay sent in the image set metadata determines which days in Worldview the images show up for. Some datasets are composites derived from multiple granules within a time period. For these, it makes sense to have the DataDay set to a single day for all granules that are included.

bignbit currently sets the DataDay based on thedates in the granule umm-g
To support LP DAAC's OPERA DIST-ANN product, there needs to be a way to set the DataDay for all granules to a single day instead of pulling it from each granule's umm-g.
This may also affect other datasets at PODAAC that don't yet use bignbit.