Roughly 'blee-una va oor'.
Sláinte = cheers (Irish); Slàinte (Scottish).
Òg-Mhadainn/h-òg-mhaidne ('new morning')
"matin vah" It means "Good morning" in Scottish Gaelic.
oidhche
It would be Slàinte mhath! in Scottish Gaelic.
Happy New Year is Bliadhna Mhath Ùr (pron. Blee-an-uh Va Oor) in Scots Gaelic. There doesn't seem to be a set expression for wishing someone a happy Hogmanay, which is New Year's Eve. Hogmanay itself is Oidhche Challainn.
meadhon-oidhche
Irish is oíche Scottish is oidhche
It is pronounced as "slawn-cha va" in English, which is a traditional Scottish Gaelic toast meaning "good health."
Scottish: Oidhche Shamhna shona dhut. Irish: Oíche Shamhna shona dhuit.
It's Gaelic. And it is spelled Dia dhuit in Irish Gaelic. It's Scotts Gaelic it's Madinn mhath, or hallo. Keep in mind that they do not pronounce their letters the same way we do in English.