What is the ruling of fasting the day which we doubt whether it is 30th of Ramadan of 1st of Shawwal?

Answer

In the name of Allah, one may continue his fasting -as in the question- unless the Eid (1st of Shawwal) is confirmed in religiously authentic ways. Fasting the first day of Eid is not permissible, a reason why some believers chose to travel at that day so he can break his fast. Some scholars (may Allah be pleased with them) draw the believers' attention to get rid of the possibility of impermissibility of fasting this day by using such means. We have given the answer to this question before. Allah knows best.