Okay lets see if I can fill in some gaps
This seemed to address the original question, but with no more than a dogmatic statement.
It's the first postulate under Quantum Mechanics you have to assume it for now (in the near future we may be able to prove it I will discuss a bit later) but for now it is the number one assumption and if it is wrong then the predictions of QM should be wrong.
You can try wading thru the first postulate in
http://arxiv.org/ftp/physics/papers/0602/0602145.pdf but probably goto the time as an operator section in the wiki link
http://en.wikipedia.org/wiki/Mathematical_formulation_of_quantum_mechanicsThe key point
The framework presented so far singles out time as the parameter that everything depends on
So the entire framework of QM is built upon the premise that time is intrinsic and real. It has to be that under QM for you to be able to define a waveform for time evolution of a system.
Note that this QM time is also outside and seperated from time within space and thats what the following parts of the wiki entry deal with that QM also says time may become observable within space but it will be a function of the QM time.
So QM real time being outside space is a fundemental thing and one which Einstein and friends disagreed with because time in GR/SR is bound as a 4th dimension in spacetime.
This set the foundation for the famous EPR paradox (
http://en.wikipedia.org/wiki/EPR_paradox) and Einstein, Podolsky and Rosen assertion that QM is incomplete and or inconsistant and there are hidden variables that are not accounted for in the framework.
Now if you go back to the framework almost all the classic quantities are there some are quantized but by and large they are the same the big difference is time which is the number one assumption of QM.
If time is not the same between QM and GR/SR then you will find a reality problem between QM and GR/SR.
In 1964 John bell released his paper "On the Einstein Podolsky Rosen paradox" in which he setout a simply analogy which showed mathematically and by using simple reasoning that EPR was incorrect and there is no local reality you can read up on it (http://en.wikipedia.org/wiki/Bell's_theorem).
Bell's theorem seemed to put an end to local realism. This is because, if the theorem is correct, then either quantum mechanics or local realism is wrong, as they are mutually exclusive.
By 1981 we had enough technical background in dealing with entangled particles to try the experiment which was done by Alain Aspect (
http://en.wikipedia.org/wiki/Alain_Aspect).
The background to Bells Theorem is so simple it has now been converted to a simple computer code and Sascha has an online site for all crackpots who don't accept it to have an attempt to solve it (
http://www.science20.com/alpha_meme/official_quantum_randi_challenge-80168)
Now we talk about "reality" and "observation" but if we cut to the bottom we saying is QM time differs from our local reality time. So while things seem wrong in terms of timing for us as observers if you look at it from QM time prespective it makes perfect sense.
So while QM time is not conclusively proved it is the only theory that currently exists that predicts such a weird outcome. There is no classic physics interpretation that allows such a strange result that local reality does not exist and makes predictable and testable experiments.
There are lots of more extensive probes on QM time being done but most involve complexity that will require some detailed discussion and I would like to see what you make of all that so far.
I will also pick up Coherence in another post once I am sure we have answered all your questions about what time is in QM.