Splatoon Global Testfire
From Inkipedia, the Splatoon wiki
Splatoon Global Testfire is a free demo available on the Nintendo eShop. It will allow players to engage in free 4-vs.-4 Turf Wars for free at scheduled time ahead of the release of Splatoon. The times are as follows: North America Friday, May 9th 2015 8-9 PM PST Saturday, May 10th 2015 4-5 AM PST Saturday, May 10th 2015 12-1 PM PST
Europe Saturday, May 9th 2015 4:00 BST Saturday, May 9th 2015 12:00 BST Saturday, May 9th 2015 20:00 BST