GetCurDateTime function - how is this?

In my failed attempt at getting the current date time from the Arduino + Edison world, I have come up with a kludge.

Please tell me if you see a better way at getting this string.  Here is the sketch.

void setup()

String GetCurDateTime()

String date = String(__DATE__);

String day = date.substring(4, 6);

String month = GetCurMonth();

String year = date.substring(7, 11);

String time = String(__TIME__);

return year + "." + month + "." + day + "." + time;

String GetCurMonth()

String dt = String(__DATE__).substring(0, 3);

if (dt == "Jan")

return"01";

elseif (dt == "Feb")

return"02";

elseif (dt == "Mar")

return"03";

elseif (dt == "Apr")

return"04";

elseif (dt == "May")

return"05";

elseif (dt == "Jun")

return"06";

elseif (dt == "Jul")

return"07";

elseif (dt == "Aug")

return"08";

elseif (dt == "Sep")

return"09";

elseif (dt == "Oct")

return"10";

elseif (dt == "Nov")

return"11";

elseif (dt == "Dec")

return"12";

else

return"99";

void loop(){