There is no difference in meaning; there is an enormous difference in use.
Many languages have grammaticalized systems of deference, which encode a variety of differences in social standing between the participants in a conversation. Britons (who never never ne-ver shall be slaves) and Americans (whose Charter Myth is that all men are created equal) scorn these ways of speaking as repulsive toadying; but we have equally elaborate codes for acknowledging and regretting the unhappy necessity of imposing burdens on our peers.
For instance: it would be unspeakably peremptory to require that your interlocutor “Give me an answer at once!” Even your own more gracious “I await your reply as soon as possible” suggests to us a frigid insistence on your own needs, only slightly tempered by a condescending indication that your impatience will, if it must, tolerate some slight delay.
(We all know that that’s not what you mean; but it’s what it would mean if a native speaker said it.)
In the same way, “What time is it?” is an abrupt demand for information; it would be acceptable only in a situation of extreme urgency or between people with an established close personal or professional relationship. With a stranger you must be more hesitant and less willing to impose; you must make it clear that you value his time no less highly than he does, that you regret the necessity of intruding upon his attention, and that you do not even go so far as to request, however humbly, the information you require: you only wonder, hypothetically, whether it is possible that he might unbend so far as to consider, hypothetically, providing it.
I was about to upvote Tromano's answer when I noticed that the OP's examples are both in the positive form. If they had been in the negative:
- I haven't played soccer for a long time.
- I haven't played soccer in a long time.
There would be no difference in meaning. If both sentences had been in the Past Simple, there would be no difference in meaning
- That was the best restaurant I've been to for/in a long time (= a long period has gone past since I went to such a good restaurant).
But the OP's sentences are in the Present Perfect tense, and only the first one is idiomatic. The second is not.
- I have played soccer for a long time. (RIGHT)
- I have played soccer in a long time. (WRONG)
The Present Perfect is often used to express a duration of time, an action that began in the past and continues to the present time. To say how long something has continued we use for, to say when the action began we use since.
I have played soccer for twenty years (=I have played this sport for a total of 20 years)
I have played soccer since 1998 (=I started playing the sport in 1998 and I have not stopped playing)
Cambridge dictionaries defines this meaning of time as
noun (PERIOD) a particular period of time for which something has been happening, or that is needed for something
- After a time, it became clear that nobody was interested in coming to the meetings.
- They stayed with us for a short time.
- That was the best restaurant I've been to for/in a long time (= a long period has gone past since I went to such a good restaurant).
- It was some time ago that I last heard from her.
- We're going on holiday in two weeks' time
Best Answer
Imagine a clock counting down from one hour to zero. When the clock hits zero, a bomb goes off. You have been sent in to defuse it.
At the beginning, you tell your boss, "Don't worry. An hour is plenty of time to defuse a bomb.
When the countdown hits five minutes and it still isn't defused, your boss tells you to hurry, because you're running out of time.
When the countdown hits zero and the bomb explodes, only then are you out of time.
In other words: "running out of time" implies that there is still a little bit of time left. Out of time means that there isn't.