You can get a good insight on the answer to this question from the "Best Times to Tweet" report. The larger the bubble the better the engagement for that time of the week.
The engagement score is the number of total interactions, retweets and favourites your account has received, divided by the total number of tweets you have sent. The larger the bubble, the highest your engagement score for that day and time is.
If you hover over a data point, you get some more information on the tweets you have posted on that day and time and the interactions they have triggered.
Please watch the video to get some more help on using this feature.