I need to highlight the cells when I enter date and it is within the other cells. Hightlight both cells that contain the same date.
@coybyington: Please do not post as community wiki. See guidelines for asking. Also, which cells in the screenshot do you want to be highlighted? Since you are asking on a LibreOffice site, presumably you are interested in solutions that use LO Calc instead of MS Excel.
See reworded question at /question/150621/.