to string local in yyyymmdd nodejs code example

Example 1: javascript convert date to yyyy-mm-dd

// `date` is a `Date` object
const formatYmd = date => date.toISOString().slice(0, 10);

// Example
formatYmd(new Date());      // 2020-05-06

Example 2: javascript format date yyyy-mm-dd

let today = new Date()
today.toISOString().split('T')[0]