// Here we're creating a new to insert in the var newCSSHome = document.createElement('link'); newCSSHome.type = 'text/css'; newCSSHome.rel = 'stylesheet'; // This is where you can determine when to use which stylesheet. // If the current hour is before 9am or 8pm (or later), use "night.css" if (currentHour < 7 || currentHour >= 18) { newCSSHome.href = '/wp-content/themes/ivemendes/css/module/home-night.css'; } // This line actually does the deed, and attaches the selected stylesheet jQuery("head").append(newCSSHome);