创建三个函数来调用PHP中的Today、Yester和Future

Create three function to call Today, Yester and Future in PHP

我是PHP的新生。我想创建3个函数来返回Today、Yesterday和Future。

有人能告诉我如何制作这些吗？

// midnight second or equal today
    function isToday($time) 
    {
        return (strtotime($time) === strtotime('today'));
    }
    //Yesterday
    function isPast($time)
    {
        return (strtotime($time) < time());
    }
    // Next day
    function isFuture($time)
    {
        return (strtotime($time) > time());
    }