Lunar Calendar

Dear Brothers in Islam, Assalamualaikum...... I wanted to know if there is any scientific reason in Islam persuing their months as per the lunar calender than the usual months which are followed in the world.

Dear scholars, can you enlighten us on the Islamic perspective on solar and lunar eclipses and how to perform the Prayer pertaining to those occasions?

As-Salamu `Alaykum. I read a hadith that says fasting 3 days a month is like fasting the entire year. And these days are the thirteenth, fourteenth and the fifteenth. Now my question is do we fast on the 13th, 14th and 15th of the American calendar or the Muslim one?