var arr = [
{date:"2020-04-28"},
{date:"2020-04-29"},
{date:"2020-04-30"},
{date:"2020-05-01"},
{date:"2020-05-02"},
{date:"2020-05-03"}
];
var find = Math.floor(+new Date()/86400000);
var finded = arr.find(e=>Math.floor(+new Date(e.date)/86400000) == find);//{date:"2020-05-01"}, если сегодня это число