This is an example of a dark themed date and time picker, designed using CSS, HTML, JavaScript, and Bootstrap framework 4. JavaScript methods are used to implement the functionality of the date picker. The body of the form is given a background-color of #C5CAE9, and font color of #000. The information card is given a box-shadow style of 0px 4px 8px 0px #7986CB. The date input field is given the styles of padding as 10px 20px, border as 1px solid #000, border-radius as 10px, background-color as #616161, font color as #fff, font-size as 16px, letter-spacing as 1px, and width as 180px. In a focus event, the input date field takes a border style of 1px solid #512DA8. The date slot of the calendar takes a background color of #eee, in a hover event. In the active mode, the date slot takes a background color of linear-gradient(#90CAF9, #64B5F6), and font color as #000. The Month value of the calendar is displayed using a font-size of 20px, and a text-transform style of uppercase to automatically convert the text to uppercase. The cursor style for the time slots is set as pointer to get the hand cursor effect on a hover event while the background color of the time slot changes to #3D5AFE, in a focus event. Source: https://bbbootstrap.com/snippets/dark-themed-date-and-time-picker-76906698