#include <WiFi.h>
#include <HTTPClient.h>
const char* ssid = "Gareth";         //Router name
const char* password =  "Slatybartfast";  //Router Password
const String PollTimeAPI = "http://api.openweathermap.org/data/2.5/weather?lat=-77.66&lon=168.22&units=metric&APPID="; // simple web call to extract weatherdata , however can double up to extract header data as well
const char * headerKeys[] = {"date"};//The data key you require from the HTTP Header
const size_t numberOfHeaders = 1;    //The number of keys in your array above
int pollApiTime;
void setup() {
 Serial.begin(115200);
 WiFi.begin(ssid, password);
 while (WiFi.status() != WL_CONNECTED) {  delay(200); Serial.print(">"); }
 Serial.print("Connected to "); Serial.println(ssid);

 }
void loop() {
  if (millis()-pollApiTime >=10000) {PrintDateTime(); pollApiTime=millis(); }
}
void PrintDateTime()
{
 if ((WiFi.status() == WL_CONNECTED)) {              //Check the current connection status
   HTTPClient http;
   http.begin(PollTimeAPI);                          //Specify the URL
   http.collectHeaders(headerKeys, numberOfHeaders); // here is how to access certain data fields in the HTTP responce header
   int httpCode = http.GET();                        //Make the request
   if (httpCode > 0) {                               //Check for the returning status code  :-)
   String headerDate = http.header("date");          //extract the date and time field
   Serial.println(headerDate);
   http.end();       }                               //free up the request
                                      }
}