https://support.hammerhead.io/hc/en-us/community/posts/29736866072731--%F0%9D%95%BE%F0%9D%96%95%F0%9D%96%8E%F0%9D%96%97%F0%9D%96%8E%F0%9D%96%99-%F0%9D%95%AC%F0%9D%96%8E%F0%9D%96%97%F0%9D%96%91%F0%9D%96%8E%F0%9D%96%93%F0%9D%96%8A%F0%9D%96%98-What-is-the-cheapest-day-to-fly-on-Spirit