For Everest Base Camp, you need a proper acclimatization time of at least two days. During Acclimatization time you need to hike up as high as possible and return back to the lower place for the overnight stay.
In Everest Base Camp you will have your acclimatization at Namche Bazaar, when you hike up to Everest View Hotel and return to Namche Bazaar. Most people think acclimatization means just resting in a lodge but you need to walk the possible altitude and hike back tolower altitude for rest. On this trek we will have our another day acclimatization in Dingboche.
During this day you will hike you to Nagarshan HillTop and spend some time there. Proper acclimatization not only helps to avoid Altitude sickness but also help the body muscles and body to adjust with the changing level of Oxygen.