The business hours of a store are from 8:00 am to 8:00 pm, what are the hours of operation throughout the day?
某商店营业时间是上午8：00至晚上8：00，全天营业的时间是多少时．
<gadget id="calculator">20 - 8</gadget>
<output>12</output>

<result>12</result>