Apparently Twitter tells us more than just the latest news and trends. It also gives a glimpse into mood swings across the globe. An analysis of 509 million tweets by 2.4 million people from 84 countries revealed some clear mood patterns. For example, tweets tend to be more positive on the weekends than during weekdays. And tweets are more optimistic early in the morning and grow more negative as the day goes on. Another good-mood peak occurs around midnight, when work-related stress is no longer dominant. Science