Thanks for sharing.
Regards,
Sara

Unfortunately most of the time servers seem to be available only temporarily and the IP address becomes invalid from time to time and I had to implement a mechanism that detects that and then requests a new address.

Another issue is that requests tend to fail quite often, probably due to high trafic. You might have realized that on Your windows pc, when You try to manually force an update of the time by a time server. Sometimes You have to click several time or change to a different server until it reports success.

I then, more or less accidentally, realized that my router – typically the gateway address – also provides ntp services by default. Since that day I am updating my time with that “server”. It’s blazing fast, almost a 100% reliable and more than good enough for all my projects.

I use the “time” – lib by Paul Stoffregen(https://github.com/PaulStoffregen/Time) together with my ntp implementation. This makes handling with time data very easy and takes care of regular ntp updates.

Hope this is of help to anyone.

Regards

Frank

if (actualMonth > 2 && actualyear %4==0 && actualyear %100 !=0)
{d=d+1;}
return d;

To complete it, it should be :
if (actualMonth > 2 && ((actualyear %4==0 && actualyear %100 !=0) || (actualyear %400==0)))
{d=d+1;}
return d;

int doy()
{
d=actualday;//actualday
//Serial.print(d);
for (int i=0;i<actualMonth-1;i++){
d=d+daysInMonth[i];
//Serial.println(d);
}
if (actualMonth > 2 && actualyear %4==0 && actualyear %100 !=0)
{d=d+1;}
return d;
}

That can come in handy if you want to start or and an action on a specific date. No need to check on day and month but just on say ‘day 200’

String maandNaam [] ={“Jan”, “Feb”, “Mrt”, “Apr”, “Mei”, “Juni”, “Juli”,”Aug”,”Sep”,”Okt”,”Nov”,”Dec”};

In Setup()
NTPch.setSNTPtime()

in loop()
//dateTime = NTPch.getNTPtime(1.0, 1); //from NTP server use this if you want ESP to continuously fetch new time
dateTime = NTPch.getTime(1.0, 1); // get time from internal clock
if (dateTime.valid) {
//NTPch.printDateTime(dateTime);
actualHour = dateTime.hour;
actualMinute = dateTime.minute;
actualsecond = dateTime.second;
actualyear = dateTime.year;
actualMonth = dateTime.month;
actualday = dateTime.day;
actualdayofWeek = dateTime.dayofWeek;
}

epoc-time does contain all the information so that it is possible to calculate
the actual date and time.
Therefore I discovered a pretty small demo-code written by Werner Rotschopf
https://werner.rothschopf.net/201802_arduino_esp8266_ntp.htm

It uses the time.h-library and another structure that makes it easier to access day. month, year, hour and a number of day of week etc.

it inkludes cofiguration of the timezome through a define

and as an additional hint:
if you want to use a if-condition like switch something on from 7:54 to 21:19
caclulating minute of day makes life easier

actualTime = hour * 60 + minute

SwitchOnTime = 7 * 60 + 54 = 474
SwitchOFFTime = 21*60 + 19 = 1279

so a otherwise complicated if-condition about hours and minutes boils down to

if (actualTime > SwitchOnTime && actualTime < SwitchOFFTime) {
//take action;
}

best regards Stefan