Conflict in wave-particle duality!?

Can anyone tell me why does a photon behave as a particle in a particular phenomenon and wave in another, example a photon behaves as a particle in photon-multiplier experiment, in general relativity and as a wave in interference experiment! Does the photon know when to behave as a particle and when as a wave, Or is it that photon behaves as a particle on Monday's, Thursday's, Friday's and as a wave on Tuesday's, Wednesday's and Saturday's and of course Sunday is a holiday for photons(Just a little humor to make this question interesting)