Is there any situation or reason where {Holy Day} would be any better than {Etheral Haze}? Or is the haze just always better?
Well if youd like to cast a {lightning bolt} at the end of their turn but prevent all combat damage they dealt, {holy day} is your best bet
Ooh didnt read the haze closely enough my apologies
I believe the haze would accomplish the same thing. It only prevents damage from creatures.
If you opponent is trying to kill you with an army of {Goblin Fireslinger} or is trying to destroy your creature with a death touched {Izzet Staticaster} then {Ethereal Haze} would be better than {Holy Day} because of the fact that the damage is not in combat.
The haze stops creatures dealing you non-combat damage, too. {Guttersnipe}
Basically just seconding Josh, haha.