How to refresh the NTP time in local timezone?

[dineshgyl]

Hi,

I have a program to send email every 5 mins.

I have set this in my setup function.

      WifiWaitConnect("Setup: ");
      WiFi.setAutoReconnect(true);
      WiFi.persistent(true);

        //smtp.debug(1);
        smtp.callback(smtpCallback);
        session.server.host_name = smtpUrl;
        session.server.port = smtpPort ;
      
        session.login.email = emailFrom;
        session.login.password = emailPass;
        session.login.user_domain = "";
   
        session.time.ntp_server = "pool.ntp.org,time.nist.gov";

        session.time.gmt_offset = 0;  
        session.time.day_light_offset = 0;
        
        session.time.timezone_env_string = "EST5EDT,M3.2.0,M11.1.0"; 
       
        SendMail("Setup",F("Email Client Initialized ") + WiFi.localIP().toString() +  ". \r\n\r\n" + StoredValues());

So the above function connects to wifi and set the email parms and send the mail.

In the loop function i call sendmail function every like 5 mins.

void loop()
{
SendMail("loop","Email from loop");
delay(300000);
}

void SendMail(String Subject, String Body) 
{

    SMTP_Message message;
    message.sender.name = "ESP8266";
    message.sender.email = emailFrom;
    message.subject = Subject ;

    message.addRecipient("ESP8266Receiver", emailTo);

    message.text.content = Body.c_str();
    message.text.charSet = "us-ascii";
    message.text.transfer_encoding = Content_Transfer_Encoding::enc_7bit;
    message.priority = esp_mail_smtp_priority::esp_mail_smtp_priority_low;
    message.response.notify = esp_mail_smtp_notify_success | esp_mail_smtp_notify_failure | esp_mail_smtp_notify_delay;

    if (!smtp.connect(&session))
    { LastSMTPEmailReasonCode = smtp.errorReason();
      return;
    }

    if (!smtp.isLoggedIn())
        LastSMTPEmailReasonCode = F("SMTP not logged in");
    else
    {
      if(!smtp.isAuthenticated())
        LastSMTPEmailReasonCode = F("SMTP Logged in, not authenticated.");
    }

    if (!MailClient.sendMail(&smtp, &message))
    {
      Serial.println("Error sending Email, " + smtp.errorReason());
    }
Serial.println(String(EmailTimestamp));
}

In the callback function I am getting the email sent timestamp and storing in variable.

void smtpCallback(SMTP_Status status)
{
  /* Print the current status */
  //Serial.println(status.info());  // ENable to DEBUG SMTP
  status.info();
  /* Print the sending result */
  if (status.success())
  {
    
    ESP_MAIL_PRINTF("Message sent success : %d failed : %d \n", status.completedCount(),  status.failedCount());
  
    for (size_t i = 0; i < smtp.sendingResult.size(); i++)
    {
      /* Get the result item */
      SMTP_Result result = smtp.sendingResult.getItem(i);
      strcpy(EmailTimestamp, MailClient.Time.getDateTimeString(result.timestamp, "%Y-%m-%d-%H.%M.%S %z").c_str());
     
     }
    
    smtp.sendingResult.clear();
  }
}

Now my problem is sometimes after wifi is connected the internet is not available then the first email sendmail in setup function fails with message unable to connect to server

Then after sometime when internet is available the sendmail function in loop() works fine. It sends emails.

But the timestamp string in callback function comes in GMT time rather than local time.

However when the internet is available during the 1st email thats being sent in the setup function then timestamp is in local time.

I want to know is there a way to refresh the timezone setting so that timestamp is fetched in local time when internet becomes available?

Both session and smtp are global variables. Will setting the below again inside loop function, refresh the timezone setting and subsequent emails sent after internet is available will be in local time?

session.time.gmt_offset = 0;  //EST  12 + ABS(offset)
        session.time.day_light_offset = 0;
        
        session.time.timezone_env_string = "EST5EDT,M3.2.0,M11.1.0"; 

[mobizt]

If you use ESP32 and your device woke up from sleep which time zone environment will be lost, please update the library to v3.3.2 when it is available in Arduino Library Manager.

[dineshgyl]

I am using ESP01S chip. Device is not going in sleep. Do you mean upgrading to 3.3.2 will solve this?

[mobizt]

It may not help in this case.

You should call this.

setenv("TZ", "Your time zone", 1);
tzset();

If you still not get the valid local time, that is the bug in ESP8266 core.

Anyway, you should update the library to latest version.

[dineshgyl]

So I can just call it in my SendMail Function?

[mobizt]

Yes, but you can call it anywhere anytime.

[mobizt]

That is UNIX functions that used in ESP8266 and ESP32 cores.

[dineshgyl]

I tried adding this in Sendmail... but still it shows GMT time when internet becomes available. However when Internet is available from the beginning then timestamp is shown in local timezone.

[mobizt]

The internal timestamp is actually taken from the system time i.e., time(nullptr).

When your system time was set internally in the library based on these options and time zone environment string.

session.time.gmt_offset = 0;  
session.time.day_light_offset = 0;

I can confirm that the system time will not change as long as those two options are unchanged, and it's not related to WiFi/ internet condition as library will look for valid system time before taking the time from NTP server.

You can set your device time yourself using configTime before calling connect.

If you believe this is the library issue, you should create minimal sketch to reproduce the issue and explain more detail in code.

[dineshgyl]

I am in New York. So EDT.

session.time.gmt_offset = -5;
session.time.day_light_offset = 1;

When the device boots, and connect to WIFI , internet is not available but the timestamp I see is in EST and not in EDT.

Will calling configTime before calling connect, sync it correctly when internet becomes available?

[mobizt]

internet is not available but the timestamp I see is in EST and not in EDT

No internet, your device can't get the time from NTP server then your system time will be the seconds count from device boot.

If you don't know what is configTime, please search google.

Calling configTime does nothing without internet.

Library will call configTime internally to get time from NTP server.

You need internet all the time to work.

[mobizt]

After calling configTime, (you need to connect to internet) and wait until valid time becomes available.

while (time(nullptr) < 1690559334)
{
  delay(1);
}

The value 1690559334 is current timestamp, or you can use any large number of seconds for a year like 60 * 60 * 24 * 365.

[dineshgyl]

Thanks, I tried disabling NTP, but then I get compile error.

In file included from c:\Users\0G2105649\Downloads\Sketch\libraries\ESP-Mail-Client.3.3.2\src\ESP_Mail_Client.h:54,
                 from c:\Users\0G2105649\Downloads\Sketch\libraries\ESP-Mail-Client.3.3.2\src\ESP_Mail_Client.cpp:38:
c:\Users\0G2105649\Downloads\Sketch\libraries\ESP-Mail-Client.3.3.2\src\extras/MB_Time.h: In member function 'int MB_Time::setTimestamp(time_t)':
c:\Users\0G2105649\Downloads\Sketch\libraries\ESP-Mail-Client.3.3.2\src\extras/MB_Time.h:239:12: error: 'settimeofday' was not declared in this scope; did you mean 'settimeofday_cb'?
  239 |     return settimeofday((const struct timeval *)&tm, 0);
      |            ^~~~~~~~~~~~
      |            settimeofday_cb

[dineshgyl]

Even this Set_time example not compile when #define ENABLE_NTP_TIME is commented in src/ESP_Mail_FS.h

/**
 * This example showes how to set the library and/or device time manually.
 *
 * Created by K. Suwatchai (Mobizt)
 *
 * Email: suwatchai@outlook.com
 *
 * Github: https://github.com/mobizt/ESP-Mail-Client
 *
 * Copyright (c) 2023 mobizt
 *
 */

/** ////////////////////////////////////////////////
 *  Struct data names changed from v2.x.x to v3.x.x
 *  ////////////////////////////////////////////////
 *
 * "ESP_Mail_Session" changes to "Session_Config"
 * "IMAP_Config" changes to "IMAP_Data"
 *
 * Changes in the examples
 *
 * ESP_Mail_Session session;
 * to
 * Session_Config config;
 *
 * IMAP_Config config;
 * to
 * IMAP_Data imap_data;
 *
 */

#include <Arduino.h>
#if defined(ESP32) || defined(ARDUINO_RASPBERRY_PI_PICO_W)
#include <WiFi.h>
#elif defined(ESP8266)
#include <ESP8266WiFi.h>
#else

#endif

#include <ESP_Mail_Client.h>

#define WIFI_SSID "MYSSID"
#define WIFI_PASSWORD "MYPASS"

#define SMTP_HOST "smtp.gmail.com"
#define SMTP_PORT 587

#define AUTHOR_EMAIL "email@gmail.com"
#define AUTHOR_PASSWORD "emailpassword"
#define RECIPIENT_EMAIL "email@gmail.com"

SMTPSession smtp;

void smtpCallback(SMTP_Status status);

#if defined(ARDUINO_RASPBERRY_PI_PICO_W)
WiFiMulti multi;
#endif

void setup()
{

    Serial.begin(115200);

    Serial.println();

#if defined(ARDUINO_RASPBERRY_PI_PICO_W)
    multi.addAP(WIFI_SSID, WIFI_PASSWORD);
    multi.run();
#else
    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
#endif

    Serial.print("Connecting to Wi-Fi");
    
#if defined(ARDUINO_RASPBERRY_PI_PICO_W)
    unsigned long ms = millis();
#endif

    while (WiFi.status() != WL_CONNECTED)
    {
        Serial.print(".");
        delay(300);
#if defined(ARDUINO_RASPBERRY_PI_PICO_W)
        if (millis() - ms > 10000)
            break;
#endif
    }
    Serial.println();
    Serial.print("Connected with IP: ");
    Serial.println(WiFi.localIP());
    Serial.println();

    // Method 1, set time using core function e.g. configTime or configTzTime before connecting to mail server
    // This method requires internet connection.
    // This method suites for ESP8266, ESP32, Raspberry Pi Pico (W)

    Serial.print("Waiting for NTP server time reading");

    configTime(3, 0, "pool.ntp.org", "time.nist.gov");

   int SNTPWaitLoopTimeout = 10000; // 10 seconds
    while (time(nullptr) <= 1670560665) 
    { 
      if (SNTPWaitLoopTimeout <= 0) 
      {
        Serial.println(F("Time synch timeout reached."));
        break;
      }
      delay(1000);
      SNTPWaitLoopTimeout -= 1000;
      Serial.println(F("Wait Time Sync - ") + String(SNTPWaitLoopTimeout));
    }

    Serial.println();
    Serial.println();

    // Method 2, set timestamp directly via smtp.setSystemTime or imap.setSystemTime
    // This method doen not require internet connection.
    // This method suites for non-system time (device local time) devices e.g. ARM, SAMD and AVR devices.
    // The timestamp is the seconds since Midnight Jan 1, 1970 and can be taken from RTC chip
    // and other providers.

    // If use this method with ESP8266 and ESP32, the device system time will be set automatically.

    // time_t ts = 1577836800;

    /*
    Set the NTP config time
    For times east of the Prime Meridian use 0-12
    For times west of the Prime Meridian add 12 to the offset.
    Ex. American/Denver GMT would be -6. 6 + 12 = 18
    See https://en.wikipedia.org/wiki/Time_zone for a list of the GMT/UTC timezone offsets
    */
    // float gmtOffset = 3.0; // GMT offset in hour

    // smtp.setSystemTime(ts, gmtOffset);

    // Note:
    // If time setting faild when using method 1 and method 2, the library internal NTP time reading will
    // be started when valid time is required during server connection.

    // To disable library internal NTP time reading, please comment or remove the following macro defined in src/ESP_Mail_FS.h
    // #define ENABLE_NTP_TIME

    MailClient.networkReconnect(true);

#if defined(ARDUINO_RASPBERRY_PI_PICO_W)
    MailClient.clearAP();
    MailClient.addAP(WIFI_SSID, WIFI_PASSWORD);
#endif

    smtp.debug(1);

    smtp.callback(smtpCallback);
}

void SendMail()
{
    Session_Config config;

    config.server.host_name = SMTP_HOST;
    config.server.port = SMTP_PORT;
    config.login.email = AUTHOR_EMAIL;
    config.login.password = AUTHOR_PASSWORD;

    config.login.user_domain = F("mydomain.net");

    SMTP_Message message;

    /* Set the message headers */
    message.sender.name = F("ESP Mail");
    message.sender.email = AUTHOR_EMAIL;
    message.subject = F("Test sending plain text Email");
    message.addRecipient(F("Someone"), RECIPIENT_EMAIL);

    String textMsg = "This is simple plain text message";
    message.text.content = textMsg;

    message.text.charSet = F("us-ascii");

    message.text.transfer_encoding = Content_Transfer_Encoding::enc_7bit;
    
    if (!smtp.connect(&config))
    {
        ESP_MAIL_PRINTF("Connection error, Status Code: %d, Error Code: %d, Reason: %s", smtp.statusCode(), smtp.errorCode(), smtp.errorReason().c_str());
        return;
    }

    if (!smtp.isLoggedIn())
    {
        Serial.println("\nNot yet logged in.");
    }
    else
    {
        if (smtp.isAuthenticated())
            Serial.println("\nSuccessfully logged in.");
        else
            Serial.println("\nConnected with no Auth.");
    }

    if (!MailClient.sendMail(&smtp, &message))
        ESP_MAIL_PRINTF("Error, Status Code: %d, Error Code: %d, Reason: %s", smtp.statusCode(), smtp.errorCode(), smtp.errorReason().c_str());
}

void loop()
{
  SendMail();
  delay(20000);
}

void smtpCallback(SMTP_Status status)
{
    Serial.println(status.info());

    if (status.success())
    {

        Serial.println("----------------");
        ESP_MAIL_PRINTF("Message sent success: %d\n", status.completedCount());
        ESP_MAIL_PRINTF("Message sent failed: %d\n", status.failedCount());
        Serial.println("----------------\n");

        for (size_t i = 0; i < smtp.sendingResult.size(); i++)
        {

            SMTP_Result result = smtp.sendingResult.getItem(i);

            ESP_MAIL_PRINTF("Message No: %d\n", i + 1);
            ESP_MAIL_PRINTF("Status: %s\n", result.completed ? "success" : "failed");
            ESP_MAIL_PRINTF("Date/Time: %s\n", MailClient.Time.getDateTimeString(result.timestamp, "%B %d, %Y %H:%M:%S").c_str());
            ESP_MAIL_PRINTF("Recipient: %s\n", result.recipients.c_str());
            ESP_MAIL_PRINTF("Subject: %s\n", result.subject.c_str());
        }
        Serial.println("----------------\n");

        smtp.sendingResult.clear();
    }
}

[mobizt]

That's ESP8266 core issue, then do not disable it.

[mobizt]

You can update to v3.3.5.

It gains 2.2k more free flash space when ENABLE_NTP_TIME was undefined.