Is it colloquially acceptable to use ETA in place of "estimated time to completion"?

Question

Literally, ETA means "estimated time to arrival". It is often used when traveling, like you want to know your ETA to your destination, or the ETA for the package delivery.However, often I find myself wanting to use ETA when I am referring to a completion date, even though literally ETA means arrival, not completion. Obviously, there is no colloquial expression, "ETC", especially since that could be confused with "et cetera" in writing.I wanted to know what you people think about this, is it colloquially acceptable to use ETA in place of "estimated time to completion"? I do believe the other party would understand, but I am more concerned with proper grammatical usage.

Answer 1

You're correct; the receiving party would understand your meaning, but, speaking in terms of proper English, this abbreviation would not be acceptable for your meaning of "completion."

Answer 2

Unfortunately, it is not colloquially accepted. Like you said, it could get confused for etcera.