I've heard that the moon's argument of periapsis changes as well as its longitude of ascending node (right ascension of the ascending node), both having periods of: $T_{\omega}=8.85$ years and $T_{\Omega}=18.6$ years. $T_{\omega}$ is the period at which the periapsis makes one full revolution and $T_{\Omega}$ is the period at which the ascending node makes a full revolution.
However, I found certain sources which say that for the moon that, $\omega=318.15^{\circ}$ and $\Omega=125.08^{\circ}$ without any significant differences between each source. These include Wolfram Alpha, and some research papers.
This seems rather contradictory, since the values seem to be static, rather than varying periodically.
I suppose that these values are relative to a certain time, perhaps J2000. If so, will the following give the current argument (15 October 2016) of periapsis and longitude of the ascending node?
Time from J2000 to current time: $t=5.306 \times 10^8 \space s$.
Because $\omega$ increases as $t$ increases & $\Omega$ decreases as $t$ increases (prograde orbit), $\omega=318.15+\frac{360t}{T_{\omega}}$ and $\Omega=125.08-\frac{360t}{T_{\Omega}}$.
If $T_{\omega}$ and $T_{\Omega}$ are converted into seconds, I obtain:
$\omega \approx 282.574^{\circ}$ and $\Omega \approx 159.431^{\circ}$.
Now, the questions.
1) Is my reasoning correct?
2) Do the parameters $\omega$ and $\Omega$ have uniform variation?
3) Are the values for $\omega$ and $\Omega$ correct for 15 October 2016 (current date)?
4) If not, how would I calculate these parameters?
