‘Auld lang syne’ is a Scottish phrase meaning: old times remembered with affection or nostalgia (Literal translation: old, long, since):

Auld Lang Syne (verses 1&2)

Should auld acquaintance be forgot,

And never brought to min’?

Should auld acquaintance be forgot,

And days o’ lang syne?

For auld lang syne, my dear,

For auld lang syne,

We’ll take a cup o’ kindness yet

For auld lang syne.

Robert Burns (1759-1796)