Код:
<!-- СМЕНА ШАПОК ПО ВРЕМЕНИ -->
<script type="text/javascript">
theTime = new Date();
Hour = theTime.getHours();
document.write('<style>#pun-title table {background-image:');
if(Hour>=0 && Hour<8){document.write('url(https://forumstatic.ru/files/0015/23/80/19070.jpg)');}
else if(Hour>=8 && Hour<18){document.write('url(https://forumstatic.ru/files/0015/23/80/90049.jpg)');}
else if(Hour>=18 && Hour<22){document.write('url(https://forumstatic.ru/files/0015/23/80/87473.jpg)');}
else if(Hour>=22 && Hour<24){document.write('url(https://forumstatic.ru/files/0015/23/80/19070.jpg)');}
document.write('}</style>');
</script>