d = new Date();

// Month is 0-based:
if(d.getMonth() == 11) // December.
	document.write("<img style=\"position: absolute; left: 53px; top: -30px;\" src=\"images/santa-hat.png\">");
else if(d.getMonth() >= 9 && d.getMonth() <= 10) { // October 1 through October 31.
	// 4 days before and including Halloween:
	if(d.getDate() >= 28 && d.getDate() <= 31)
		document.write("<img style=\"position: absolute; left: 100px; top: 86px;\" src=\"images/candy-corn-teeth.png\">");
}
else if(d.getMonth() == 6 && d.getDate() >= 0 && d.getDate() <= 5) // July 1-6
	document.write("<img style=\"position: absolute; left: 95px; top: -35px;\" src=\"images/uncle-sam-hat.png\">");
else
	;