When would you post 300 groups post in USA

Not being in the USA (i'm UK) I often wonder when is the best time to post to FB in the groups. At the moment I usually make my first set of posts (about 80) around 11am EST till 4pm. The second set (about 80) I start at 4pm EST until 9pm and then the last set (about 160) I start at 7pm until 12pm. I dont know when the big games might be on or the major TV shows etc that might affect posting times or even when people are on lunch breaks generally etc. I know what it is for the UK but not for the US.

How do those posting times look and should I increase/decrease/change certain times.

Thanks