You can't change the number of hours in a day, but you can fill them more efficiently, with less stress and mental effort. You've likely heard this before, and perhaps your past efforts at time management have been, well, a waste of time. But most people's attempts to increase productivity get derailed by two virtues of modern living: technology and options. Today's onslaught of tech – smartphones, iPads, search engines, social media – is fragmenting our attention spans, gumming our mental gears with useless facts, and turning us into surface-level thinkers. At the same time, all the communication choices we have today – email, IM, text, Skype, or Gmail chat – are thwarting efficiency. But we don't have to give up technology to regain control. "You need to set expectations of yourself and other people," says Daniel Markovitz, a blogger on time management for the 'Harvard Business Review.' "You need to say, 'Here's the Bat Phone number. Use it if there's an emergency. Otherwise, leave me alone to do my job.'" Here, eight ways to manage time.