I understand that Jewish religion has two calendars; one is Civil for Kings, childbirth, contracts etc. and second for festivals.
what are the months of these calendars and how they are related datewise with current Christian calendar?
To quote Rosends (who I assume is Danno):
"There are different moments for the computing of the beginning of the year and for reckoning years (as in X years of a ruler's kingship or the celebration of the new year for the trees) but the months are the same for both."
"Check out the link I posted for a discussion and a list (including approximate correlations -- as a secular calendar is solar and the Jewish one is an adjusted lunar, there is a general correlation but not a strict one."