... OB used an idea to take into account the known gravitational lensing time delay to get combined radio and optical light curves and then to use them for determination of the p ossible radio-from-optical time delay. ... We fix some moment of time as t0 . ... So we can calculate the needed correction: S (t) = V · (t - t0 ) 365d (2) to b e added to dates in the optical light curves: ti = ti + S (ti ) (3) Assuming that a p ortion of radio flux decreases as a p ower-law function of time with exp onent . ...