No two days are the same. According to directom.com, you should avoid posting content on Tuesdays. Other days have varied favorable windows.
For example—for Monday postings, you’ll want to post between 11:50AM-12:10PM. Wednesdays are different. The window is a little longer, between 11:30AM-12:30PM.
Interestingly, as the week progresses, the publishing window increases. Thursday, anytime after 3:00PM is a favorable time, and on Friday, the range falls between 3:00-6:00PM.
Weekends tend to be underutilized by many brands, but the secret to weekend success is to publish lighter stuff or upcoming social events.