code: function _toDate (ndate, nrandom, nchecksum, epoc, id) {
    // Guard
    if (!_isValid(ndate, nrandom, nchecksum, id)) throw new Error('identity#toDate: Invalid Id');
  
    // Calculate
    var bits = baseURL.decode(id),
      dateBits = bits.slice(0, ndate);
    return new Date(parseInt(dateBits, 2) + epoc.getTime());
  }
docs: Get date from id
  @private
  @param  {integer} ndate     Size of date bits
  @param  {integer} nrandom   Size of random bits
  @param  {integer} nchecksum Size of checksum bits
  @param  {Date} epoc         Epoc to use
  @param  {string}  id        BaseURL encoded Id to test
  @return {Date}              The date of id creation