"Time immemorial" is an expression used to refer to a very long period of time, often from the distant past. However, there are many other synonyms to describe this concept. Some of the alternatives include "since time began," "since the beginning of recorded history," "since the dawn of time," "since the earliest days," "for centuries upon centuries," "since the ancients," and "from time out of mind." All these expressions suggest an incredibly lengthy period and are useful in writing or speaking when trying to convey a sense of history or tradition.