After Master Zhang was laid off, he set up a night stall on the street. He worked from 8:00 every night to 4:00 the next morning. How many hours did he work every day?
张师傅下岗后在街头摆夜摊，从每天晚上8：00干到第二天凌晨四时，他每天工作多少小时．
<gadget id="calculator">24 - 20</gadget>
<output>4</output>

<gadget id="calculator">4 + 4</gadget>
<output>8</output>

<result>8</result>