Splatoon release = May 28, 2015 @ 12:00 AM JST
Next Comgnet pre-order update = May 28, 2015 @ 8:00 AM JST
I guess it has to do with when the store opens up or something, then? Or am I missing something.
Ugh, I'm tired and I completely mixed my days up with it technically being Wednesday now (27th). My fault, sorry.
Splatoon releases on Thursday, 28th. COMG page is updated the day after at 8.00 (so it was updated on the 27th), but shows the ranking for the day before (this is the part I was confused on because of the days - and also wrong about, but let's ignore that ).
If you look at the top of the chart, it says:
"It is a ranking of at closing time May 26, 2015"
So it's the ranking at close of play on Tuesday. There will be another one tomorrow which will be its ranking at close of play on Wednesday, and that'll be its final ranking.