Due to the month of Ramadan and your busy schedule, you have no plans to travel anywhere recently but you want to visit Cox's Bazar beach with your family during the Eid holidays. Before this you wanted to go to Cox's Bazar beach but could not go for some reason, but I hope you must visit the place this time. 5-7 days is enough time to explore Cox's Bazar beach. I have been there twice so far and stayed there for a maximum of three days so haven't seen all the beaches there. One of the best features out there are the adventurous activities. Do try parasailing if you go there. Good luck.