The simplest solution would be to scale the time by a factor of 1e15. This must be considered in the function to be integrated also, but it is very easy to calculate the corresponding derivatives to the time.
But there could be other problems, e.g. if you want to observe a timespan of e.g. 1 sec. Then oscillations in the magnitude of 1e-15 will require about 30'000 years of processing time, when ODE45 can solve the dynamics with 2000 steps per second.
