Confidence votes 64. A lunar cycle is approximately 29.5 days, so to go from full moon to new moon (mid-cycle) would take just under 15 days. And it would take just under 15 days to go back to full moon and complete the cycle.14 days.he full lunar cycle is roughly 4 weeks, and from full-moon to new-moon is half the cycle, so it would take (roughly) 2 weeks to go from full to new moon. 3 people found this useful. Edit. Share to:  1 Thirteen Moons by Charles Frazier Book Review Thirteen Moons is the second novel of American novelist Charles Frazier.