Momentary vs Temporary

Is there any difference? Which would be better to describe a requirement for 1 or 2 days. Suppose I need to inform my Operations team, that I need a particular requirement to be implemented but I want it only for a day or two?

From ODO I get:

Temporary: Lasting for only a limited period of time; not permanent.

and

Momentary: Lasting for a very short time; brief.

So both seem to have the same meaning. Which one would be appropriate here.

Statement 1: My team's requirement for implementing ABC system is temporary.

Statement 2: My team's requirement for implementing ABC system is momentary.

Limited is very different to short.

Momentary: Lasting for a very short time; brief. ¹
Brief == not lasting for long.

Temporary: Lasting for only a limited period of time; not permanent. ¹
Limited == restricted in... amount (But has no defined amount of time it is limited for).

Momentary is a very short period of time. Temporary means it can be there indefinitely - not necessarily planned, but it will stop existing at some point.

The second hand was momentarily pointing to 12 ²

Versus

The scaffolding is on the house temporarily, while they have their roof redone. ²

^{1: Google Dictionary, momentary and temporary. Brief and Limited.
2: My Quotes}

Momentary means "just" touching -- as when a billiard ball bounces off another.

{So, depending on the physics of the situation involved, it's "just" touching. So, two billiard balls "momentarily" touching is 0.1 seconds (or whatever that is - ask an engineer). Whereas - for example - imagine describing a naval collision during a battle: the two ships "momentarily" touching (imagine all the grinding of metal, etc) would likely physically occur over - let's say - some 10 seconds. For people who work with continental plate tectonics, a "momentary" touch might be 100,000 years.}

Temporary simply means "not permanent."

Temporary has utterly no connection to whether short or long.

You know, like a "temporary teacher" or "the temporary offices" or "a temporary 87 million year break in the galactic cycle" or whatever.

BTW the answer to your question at the end, is of course sentence (1)

My team's requirement for implementing ABC system is temporary.

(FTR that sentence is generally completely meaningless if you use the word momentary - unless, bizarrely, you were talking about database transactions or something obscure.)