picker

$(document).ready(function(){
  var today = new Date();

  format = function(date){
    var day = ('0' + date.getDate()).slice(-2);
    var month = ('0' + (date.getMonth() + 1)).slice(-2);
    var year = date.getFullYear();
    return (year + '-' + month + '-' + day);
  }

  $('#checkout').val(format(today));
  $('#checkin').val(format(today));

  $('#minusWeek').click(function(){
    var lastWeek = new Date();
    lastWeek.setDate(lastWeek.getDate() - 7);
    $('#checkin').val(format(lastWeek));
  });

  $('#minusMonth').click(function(){
    var lastMonth = new Date();
    lastMonth.setMonth(lastMonth.getMonth() - 1);
    $('#checkin').val(format(lastMonth));
  });

  $('#view').click(function(){
    alert('Start: ' + $('#checkin').val() + "\n" + 'End: ' + $('#checkout').val());
  });
});