The amount of time a neutrino has to oscillate is directly related to the distance the neutrino travels and the energy of the neutrino itself. Measuring the distance is easy. The hard part is measuring the neutrino energy.
The observation of the appearance of an electron neutrino proves conclusively that the NOvA experiment can measure electron neutrino appearance and confirms oscillations at greater than 3 sigma with primary analysis or 5 sigma with secondary analysis.
The physics community got a jolt last year when results showed for the first time that neutrinos and their antimatter counterparts, antineutrinos, might be the odd man out in the particle world and have different masses.