Answers for "moment add t between date and time"

moment date add

var new_date = moment(startdate, "DD-MM-YYYY").add(5, 'days');

Moment.js: Date between dates

You can use one of the moment plugin -> moment-range to deal with date range:

var startDate = new Date(2013, 1, 12)
  , endDate   = new Date(2013, 1, 15)
  , date  = new Date(2013, 2, 15)
  , range = moment().range(startDate, endDate);

range.contains(date); // false