The best time frame to post to social networks

The optimal time to post on social networks is early afternoon if it is the local time for most of your customers because "The more bored you have to work, the more people like online facebook" (According to Buddy Media)

Explain terms

1. EST Time: The Western Hemisphere's (ET) time zone falls into the majority of the regions along the eastern coast of North America and the west coast of South America. Eastern time zone is calculated by taking the International Coordinated Time (UTC) minus 5 hours and used as standard time
2. Fortune 500: is the ranking list of 500 largest companies in the United States according to the total income of each company