Scientists, including those of Indian-origin, have discovered the secret behind attracting maximum 'likes' on Facebook - post on weekdays during working hours or between 7 pm and 8 pm. Researchers from Lithium Technologies in San Francisco first studied user behaviour including post-to-reaction times. They also compared reaction behaviour across different networks, Facebook and Twitter, and for users in different cities, performing an analysis on over one billion posted messages and observed reactions. Based on this analysis, the researchers then came up with 'personalised posting schedules' to assess if they had an effect on reactions to posts.