KATHMANDU - As other Everest hopefuls were trudging up to base camp in April, Singapore-based Brooks Entwistle was at home, planning his daughter’s 13th birthday party and preparing for his company’s annual general meeting. But at night he would climb into a hypoxic, or low oxygen, tent meant to mimic the thin air at high altitude. Now on Everest, Entwistle, a partner with Singapore’s Everstone Group, is hoping to summit the world’s highest peak in just 35 days - half the time of a conventional climb. For decades, the dream of reaching the summit of Mount Everest has required at least two months on the mountain doing a series of acclimatisation rotations to get used to the harsh low-oxygen environment at the top of the world.