Definition of data day
Some discontinuities (either overlaps or gaps) appear in the data along the International Date Line, see the problem here: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100032052.pdf
Part 3 of this document shows how this problem has been solved for MODIS C6 data https://modis-images.gsfc.nasa.gov/Webinar2014/MOD08_Level_3.pdf
Do we want to take care of this problem on our side or should we let the users (who might not even be aware of this issue) handle it?