Be mindful that Monday is Martin Luther King Jr Day in the US. Your fans and customers will see lots of great MLK-related posts in their feed throughout the day. Don’t be the brand that shouts about a sale or 10% off or some loud sales pitch in the midst of this stream of content. Share an inspirational quote or image or something else that your fans will appreciate.
On the other end of the content spectrum, the State of The Union Address is Tuesday night. This means your fans will see more argumentative political posts than usual on Wednesday and your posts may get buried deeper than usual. If you have timely content or messages you need to get out, Wednesday would be a good day to boost a Facebook post. Some positive messages might play well here too to rise above the political debate.