Arduino: configTime and time seem to ignore DST

Created on 12 Sep 2016  Â·  12Comments  Â·  Source: esp8266/Arduino

Basic Infos

configTime and time seem to ignore DST

Hardware

Hardware: ESP-12
Core Version: latest master

Description

doing a config time, with DST offset does not seem to be actually doing anything to returned time. Time zone offset applies alone.

Sketch


#include <Arduino.h>

void setup() {
  configTime(2 * 3600, 1 * 3600, "pool.ntp.org", "time.nist.gov");
  delay(2000);
  time_t now = time(nullptr);
  Serial.println(ctime(&now));
}

void loop() {

}

Debug Messages

Expected GMT + 3 to be printed. It actually prints GMT + 2

Cheers

core easy bug
Source
picture tzapu

All 12 comments

For me it's working okay.

Try this:

#include <ESP8266WiFi.h>
#include "pass.h" /* ssid=; pass=; */
#include "time.h"

time_t this_second = 0;
time_t last_second = 0;
int dst=3600;

void setup() {
     Serial.begin(19200);
     WiFi.mode(WIFI_STA);
     WiFi.begin(ssid, pass);
     while (WiFi.status() != WL_CONNECTED)
     {
         Serial.print(".");
         delay(500);
     }
     /* let us set: timezone in sec, daylightOffset in sec, 
server_name1, server_name2, server_name3 */
     configTime(7200, 3600, "time.nist.gov", "time.windows.com", 
"de.pool.ntp.org");
     // wait until network has actual time
     while(!this_second)
     {
         time(&this_second);
         Serial.print("-");
         delay(100);
     }
     Serial.println();
}

void loop() {
     time(&this_second); // until time is set, it remains 0
     if (this_second != last_second)
     {
         last_second = this_second;
         if ((this_second % 60) == 0)
         {
             Serial.print(ctime(&this_second));
         }
     }
     delay(500);
}

The network needs some seconds to initialize the internal time.
I noticed, that the esp core needs about one hour, to update the time.

Obviously there is a fixed date when DST changes,
I suspect it corresponds to Shanghai time...

On 12.09.2016 at 09:40 wrote tzapu:

  Basic Infos

configTime and time seem to ignore DST

    Hardware

Hardware: ESP-12
Core Version: latest master

  Description

doing a config time, with DST offset does not seem to be actually doing
anything to returned time. Time zone offset applies alone.

  Sketch

include

void setup() {
configTime(2 * 3600, 1 * 3600, "pool.ntp.org", "time.nist.gov");
delay(2000);
time_t now = time(nullptr);
Serial.println(ctime(&now));
}

void loop() {

}

  Debug Messages

Expected GMT + 3 to be printed. It actually prints GMT + 2

Cheers

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Juppit picture Juppit on 12 Sep 2016

ATM I have only an old ESP-01 with lots of jumpers...

But I can confirm, parameter dst dosn't have any effect in the last SDK.

This behavior has changed in the last time. I dont know when, but there
was little change in the SDK.

On 12.09.2016 at 18:06 wrote Peter:

For me it's working okay.

Try this:

#include <ESP8266WiFi.h>
#include "pass.h" /* ssid=; pass=; */
#include "time.h"

time_t this_second = 0;
time_t last_second = 0;
int dst=3600;

void setup() {
    Serial.begin(19200);
    WiFi.mode(WIFI_STA);
    WiFi.begin(ssid, pass);
    while (WiFi.status() != WL_CONNECTED)
    {
        Serial.print(".");
        delay(500);
    }
    /* let us set: timezone in sec, daylightOffset in sec, server_name1,
server_name2, server_name3 */
    configTime(7200, 3600, "time.nist.gov", "time.windows.com",
"de.pool.ntp.org");
    // wait until network has actual time
    while(!this_second)
    {
        time(&this_second);
        Serial.print("-");
        delay(100);
    }
    Serial.println();
}

void loop() {
    time(&this_second); // until time is set, it remains 0
    if (this_second != last_second)
    {
        last_second = this_second;
        if ((this_second % 60) == 0)
        {
            Serial.print(ctime(&this_second));
        }
    }
    delay(500);
}

The network needs some seconds to initialize the internal time.
I noticed, that the esp core needs about one hour, to update the time.

Obviously there is a fixed date when DST changes,
I suspect it corresponds to Shanghai time...

On 12.09.2016 at 09:40 wrote tzapu:

  Basic Infos

configTime and time seem to ignore DST

    Hardware

Hardware: ESP-12
Core Version: latest master

  Description

doing a config time, with DST offset does not seem to be actually doing
anything to returned time. Time zone offset applies alone.

  Sketch

include

void setup() {
configTime(2 * 3600, 1 * 3600, "pool.ntp.org", "time.nist.gov");
delay(2000);
time_t now = time(nullptr);
Serial.println(ctime(&now));
}

void loop() {

}

  Debug Messages

Expected GMT + 3 to be printed. It actually prints GMT + 2

Cheers

—
You are receiving this because you are subscribed to this thread.
Reply to this email directly, view it on GitHub
https://github.com/esp8266/Arduino/issues/2505, or mute the thread
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e

Am 12.09.2016 um 18:06 schrieb Peter Dobler:

For me it's working okay.

Try this:

#include <ESP8266WiFi.h>
#include "pass.h" /* ssid=; pass=; */
#include "time.h"

time_t this_second = 0;
time_t last_second = 0;
int dst=3600;

void setup() {
    Serial.begin(19200);
    WiFi.mode(WIFI_STA);
    WiFi.begin(ssid, pass);
    while (WiFi.status() != WL_CONNECTED)
    {
        Serial.print(".");
        delay(500);
    }
    /* let us set: timezone in sec, daylightOffset in sec, server_name1,
server_name2, server_name3 */
    configTime(7200, 3600, "time.nist.gov", "time.windows.com",
"de.pool.ntp.org");
    // wait until network has actual time
    while(!this_second)
    {
        time(&this_second);
        Serial.print("-");
        delay(100);
    }
    Serial.println();
}

void loop() {
    time(&this_second); // until time is set, it remains 0
    if (this_second != last_second)
    {
        last_second = this_second;
        if ((this_second % 60) == 0)
        {
            Serial.print(ctime(&this_second));
        }
    }
    delay(500);
}

The network needs some seconds to initialize the internal time.
I noticed, that the esp core needs about one hour, to update the time.

Obviously there is a fixed date when DST changes,
I suspect it corresponds to Shanghai time...

On 12.09.2016 at 09:40 wrote tzapu:

  Basic Infos

configTime and time seem to ignore DST

    Hardware

Hardware: ESP-12
Core Version: latest master

  Description

doing a config time, with DST offset does not seem to be actually doing
anything to returned time. Time zone offset applies alone.

  Sketch

include

void setup() {
configTime(2 * 3600, 1 * 3600, "pool.ntp.org", "time.nist.gov");
delay(2000);
time_t now = time(nullptr);
Serial.println(ctime(&now));
}

void loop() {

}

  Debug Messages

Expected GMT + 3 to be printed. It actually prints GMT + 2

Cheers

—
You are receiving this because you are subscribed to this thread.
Reply to this email directly, view it on GitHub
https://github.com/esp8266/Arduino/issues/2505, or mute the thread
https://github.com/notifications/unsubscribe-auth/AKUzpA7s1ZL6xtc3f3s0kDE3lGnKd1pIks5qpQH1gaJpZM4J6T42.

Juppit picture Juppit on 12 Sep 2016
😕1

I am also experiencing this same behaviour. DST is not being taken into account.

Booli picture Booli on 21 Jun 2017

Same problem here. I just adjusted the timezone by 1 hr to account for it.

Seems like at least in time.c this variable gets set and never used again.

s_daylightOffset_sec = daylightOffset_sec;

Granted I haven't looked deeper into the code.

FriedCircuits picture FriedCircuits on 26 Jul 2017

I still see the code referenced in the previous comment in latest git: the static variable s_daylightOffset_sec
is init, set, but never used.
Also, in file time.c function _gettimeofday_r() this looks wrong to me, probably a copy-pasto:
tp->tv_usec = micros() * 1000;

devyte picture devyte on 13 Oct 2017

As long as there is no function in the SDK to set DST, sntp_get_current_timestamp will only be correct in Shanghai. :-)
I made a PR to correct _gettimeofday_r.

Juppit picture Juppit on 13 Oct 2017

A quick search for "s_daylightOffset_sec" in the repository https://github.com/esp8266/Arduino/search?utf8=%E2%9C%93&q=s_daylightOffset_sec&type= shows DST it is still not used.

An interesting function in ../core/sntp.c is:
void ICACHE_FLASH_ATTR sntp_set_daylight(int daylight){
if (sntp_get_timetype()){
RTC_DST_SET(daylight);
}
}

that seems to write the ESP8266 RTC memory, being RTC_DST_SET defined as:
do {uint32 value = READ_PERI_REG(RTC_STORE3);

However, I haven't found where sntp_set_daylight is invoked.

By the way, some native (i.e., system_) functions seem interesting:

`#include

ifdef ESP8266

extern "C" {

include "user_interface.h"

}

endif

uint32 thetime, RTCtime, RTCcali;
time_t now;

void setup() {
// WiFi.begin(); // wifi disabled for example
// configTime(3*3600, 0, "not.avail.ntp");
Serial.begin(115200);
}

void loop() {
Serial.println();

now = time(nullptr);
thetime = system_get_time();
RTCtime = system_get_rtc_time();
RTCcali = system_rtc_clock_cali_proc();

Serial.print("time(): ");
Serial.print(ctime(&now));

Serial.print("system_get_time(): ");
Serial.println(thetime);

/*If system_get_rtc_time returns 10 (it means 10 RTC cycles), and
system_rtc_clock_cali_proc returns 5 (means 5us per RTC cycle), then the
real time is 10 x 5 = 50 us.
*/
Serial.print("system_get_rtc_time(): ");
Serial.println(RTCtime);

Serial.print("system_rtc_clock_cali_proc(): ");
Serial.println(RTCcali);

Serial.print("mul: ");
Serial.println(RTCtime * RTCcali);

delay(1000);
}`

mlinaje picture mlinaje on 4 Nov 2017

Juppit mentions:

while(!this_second)
{
time(&this_second);
Serial.print("-");
delay(100);
}

That is not a good test. this_second will be set to nonzero the first time time(&this_second) is executed regardless of the SNTP code. Something like this is more of a starting point if you set the global variables appropriately.

void
burtTime()
{
static bool gDash = true;

configTime(-5 * 3600, 3600, "pool.ntp.org", "time.nist.gov", "time.windows.com");
while(this_second < checkTime){ // wait until either network has actual time or this_second was merely bumped up
time(&this_second);
Serial.print(gDash ? '-' : '+');
delay(100);
}
if (this_second > checkTime) {
Serial.println();
Serial.println(this_second);
Serial.print(ctime(&this_second));
}
else ++checkTime;
gDash = !gDash;
}

In setup()
time(&this_second);
checkTime = this_second + 1;
burtTime();

In loop()
if (this_second < checkTime)
burtTime();

Or simply wait for the configTime() call to finish doing its thing.

Burt-Silverman picture Burt-Silverman on 2 May 2018

DST offset doesn't work for me too.

FernandoGarcia picture FernandoGarcia on 14 Sep 2018

4637

tablatronix picture tablatronix on 18 Oct 2018

Yeah, this is also happening for me. DST is completely ignored.

chrisspen picture chrisspen on 14 Mar 2019

SNTP support and example have receive updates, and this thread is old.
Closing but feel free to open a new issue based on git-current sntp code and example.

Current code allows to update sntp startup and update time,
also once your timezone is set (with "continent/city"), DST is automatically handled and automatically updated on transition time without reflash/reboot.
check example.

https://github.com/esp8266/Arduino/pull/6373#issuecomment-536235781
https://github.com/esp8266/Arduino/blob/1aeea124b358c3dc63e1c6fb96376695cf24840b/libraries/esp8266/examples/NTP-TZ-DST/NTP-TZ-DST.ino#L42

d-a-v picture d-a-v on 1 Oct 2019
👍1
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