Why does htop show an exclamation mark next to uptime?

Htop is an excellent interactive system monitor process viewer and process manager. It is a modern and good-looking replacement to traditional and old-fashioned TOP found in every UNIX/LINUX systems.

But I saw this (!) exclamation mark next to uptime and confused what it is at first…

But when I read their code as well as documentations, I found that htop adds an exclamation mark if the uptime is greater than 100 days. Here is code copy that shows us that exclamation mark.

int UptimeMeter_attributes[] = {
   UPTIME
};

static void UptimeMeter_setValues(Meter* this, char* buffer, int len) {
   double uptime = 0;
   FILE* fd = fopen(PROCDIR "/uptime", "r");
   if (fd) {
      fscanf(fd, "%64lf", &uptime);
      fclose(fd);
   }
   int totalseconds = (int) ceil(uptime);
   int seconds = totalseconds % 60;
   int minutes = (totalseconds/60) % 60;
   int hours = (totalseconds/3600) % 24;
   int days = (totalseconds/86400);
   this->values[0] = days;
   if (days > this->total) {
      this->total = days;
   }
   char daysbuf[15];
   if (days > 100) {
      sprintf(daysbuf, "%d days(!), ", days);
   } else if (days > 1) {
      sprintf(daysbuf, "%d days, ", days);
   } else if (days == 1) {
      sprintf(daysbuf, "1 day, ");
   } else {
      daysbuf[0] = '\0';
   }
   snprintf(buffer, len, "%s%02d:%02d:%02d", daysbuf, hours, minutes, seconds);
}

MeterClass UptimeMeter_class = {
   .super = {
      .extends = Class(Meter),
      .delete = Meter_delete
   },
   .setValues = UptimeMeter_setValues, 
   .defaultMode = TEXT_METERMODE,
   .total = 100.0,
   .attributes = UptimeMeter_attributes,
   .name = "Uptime",
   .uiName = "Uptime",
   .caption = "Uptime: "
};

I hope you get it now why it is showing that exclamation mark there.