Apart from late-night parties good night's sleep and some real action the time between midnight to 4 a.m. is also known for another thing - suicide. According to researchers suicides are far more likely to occur between midnight and 4 a.m. than during the daytime or evening. 'This appears to be the first data to suggest that circadian factors may contribute to suicidality and help explain why insomnia is also a risk factor for suicidal ideation and behaviour' said Michael Perlis an associate professor at University of Pennsylvania in Philadelphia. (Read: Why have adolescent suicides gone up by four times