If you count intergers (whole numbers) as going even, odd, even odd ... etc. then zero would count as even. However, if you were to draw graphs of y=xn, where n is any integer, e.g. -3, 0, 5, then you see patterns that go with every odd number (e.g. the '� shape with y=xeven n) and patterns that go with every odd number, but y=x0 is always a straight horizontal line, y=1, because xn is always 1.
... So I don't really know what zero counts as. Even, probably.