Is there any semantic difference between "I need a minute" and "Just a minute"? I have no context.
I guess that the second phrase is a request of waiting to a few minutes: 1, 2 or many minutes. It's an unofficial style.
'I need a minute' has the more exact length of time. It isn't 2 or 3 minutes. It is punctually, official exact one minute!
Am I right?
Update1. I completed a little survey... So, I found out that 'I need a minute' is very exact. I have fear to post references to different sites for evidence (can be off-top).
Update2. Just a minute (idiom) = wait a minute. In other words. This imperative mood can't be polite.