Events timing

Is there a way to edit the timezone on events or can we get a all day button. We are a national nonprofit and we have events listed on our website that go all day so we put them in and looks fine on our end. We are on mountain time so then when our supporters on EST, CST, PST of any others look the timing is off. There really needs to be a way to set it to be all day and then it works out to show 12-12 on whatever timezone the individual searching is on.