system-uicons/src/images/icons/calendar_add.svg

<svg height="21" viewBox="0 0 21 21" width="21" xmlns="http://www.w3.org/2000/svg"><path d="m2.5.5h12c1.1045695 0 2 .8954305 2 2v12c0 1.1045695-.8954305 2-2 2h-12c-1.1045695 0-2-.8954305-2-2v-12c0-1.1045695.8954305-2 2-2zm-2 4h16m-8 3v6.0563492m3-3.0563492h-6" fill="none" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" transform="translate(2 2)"/></svg>