text: const DateExp = require('./date-exp');
  
  console.log(new DateExp('yyyy-MM-dd HH:mm:ss.SSSZ-PeD+P1D').toString());
  // now
  console.log(new DateExp('yyyy-MM-dd HH:mm:ss').exec());
  // today
  console.log(new DateExp('yyyy-MM-dd').exec());
  // format
  console.log(DateExp.format(new DateExp('yyyy-MM-dd HH:mm:ss.SSSZ').exec(), 'yyyy-MM-dd HH:mm:ss.SSSZ'));
  // last Monday
  console.log(DateExp.format(new Date(), 'yyyy-MM-dd - PeD + P1D'));
  console.log(DateExp.format(new DateExp('yyyy-MM-dd - PeD + P1D').exec()));
  // test Feb
  console.log(DateExp.format(new DateExp('yyyy-03-31 - P1M').exec()));
  // test Feb
  console.log(DateExp.format(new DateExp('yyyy-03-31 - P1M').exec(new Date(2000, 1, 1))));