回答

思路就是时间段之间的时间差乘以随机就可以了，代码如下：

<script type="text/javascript">
        //时间戳转换成时间
        function timestampTotimestr(timestamp) {
            var date = new Date(timestamp);
            Y = date.getFullYear() + '-';
            M = (date.getMonth()+1 < 10 ? '0'+(date.getMonth()+1): date.getMonth()+1) + '-';
            D = date.getDate() + ' ';
            h = (date.getHours() < 10 ? '0' + date.getHours(): date.getHours()) + ':';
            m = (date.getMinutes() < 10 ? '0' + date.getMinutes(): date.getMinutes()) + ':';
            s = date.getSeconds() < 10 ? '0' + date.getSeconds(): date.getSeconds();
            return Y+M+D+h+m+s;
        }


        //时间转换成时间戳
        function timestrTotimestamp(str) {
            return  (new Date(str)).getTime();
        }


        function randomDate(start, end, startHour, endHour) {
            var date = new Date(+start + Math.random() * (end - start));
            var hour = startHour + Math.random() * (endHour - startHour) | 0;
            date.setHours(hour);
            return date;
        }
        //生成2021-10-12值25之间，时辰是10点到20点的随机时间
        console.log(timestampTotimestr(randomDate(timestrTotimestamp("2021-10-12 00:00:00"), timestrTotimestamp("2021-10-25 00:00:00"), 10, 20)));
 </script>