docs: function gpsTimestampToWnTow(gpsTimestamp) {
    var gpsTimeMs = gpsTimestamp.getTime() / 1000 - gpsEpochSeconds;
    var wn = Math.floor(gpsTimeMs / weekSeconds);
    var tow = gpsTimeMs - wn * weekSeconds;
    return { wn: wn, tow: tow };
  }