m.js

require('https://raw.github.com/timrwood/moment/2.0.0/min/moment.min.js');

function m() {
  var ops = {'+': 'add', '-': 'subtract'};
  var args = Array.prototype
    .slice
    .call(arguments).map(function(a) {
    if (!ops[a] && !a.utc) {
      return moment(a);
    } else return a;
  });
}

m('3 days');