Praise be to Allah.
The day of ‘Arafaah and the fasting that goes with it should be observed in each country according to the local times of fajr and maghrib. Fasting on this day expiates the sins of two years, as the Prophet (Peace & Blessings of Allaah be upon Him) said: "Fasting the day of ‘Arafaah, I hope, will expiate the sins of the year before it and the year to come, and fasting the day of ‘Aashooraa’ (the tenth day of Muharram), I hope, will expiate the sins of the year before it." (Reported by Muslim, 1976).
And Allaah knows best.