[ruslan_mart]

var table = document.getElementById('ttable'),
	rows = table.rows,
	currentDate = new Date,
	currentTime = currentDate.getHours() + ':' + currentDate.getMinutes();
for(var i = 0, lastIndex; i < rows.length; i++) {
	if(rows[i].cells[1].innerHTML <= currentTime) {
		lastIndex = i;
	}
}

if(lastIndex in rows) {
	rows[lastIndex].style.backgroundColor = 'yellow';
}