How to get over jetlag in time to give presentation abroad?

Sun & melatonin. Jet lag is the mismatch between your internal biologic clock and the external world. Your internal clock is set by sunlight, espeically morning and evening light as well as your body's natural sleep hormone-melatonin. Exposure to sunlight morning and evening and using melatoinin prior to sleep you can hasten your adaptaion. Jet lag causes decreased memory and analytic skills for the first few days.