if dat is within 30 days from today momentjs code example

Example 1: moment subtract days

var startdate = moment();
startdate = startdate.subtract(1, "days");
startdate = startdate.format("DD-MM-YYYY");

Example 2: momentjs number of days between two dates

var given = moment("2018-03-10", "YYYY-MM-DD");
var current = moment().startOf('day');

//Difference in number of days
moment.duration(given.diff(current)).asDays();