configTime / sntp_set_timezone supports only full hour timezones (+/- 30min) timezones not supported

[jyberg]

Basic Infos

• This issue complies with the issue POLICY doc.
• I have read the documentation at readthedocs and the issue is not addressed there.
• [ x] I have tested that the issue is present in current master branch (aka latest git).
• [ x] I have searched the issue tracker for a similar issue.
• If there is a stack dump, I have decoded it.
• [ x] I have filled out all fields below.

Platform

• Hardware: [ESP-12|Esp8266|NodeMcu]
• Core Version: [2.20500.0]
• Development Env: [Platformio]
• Operating System: [Windows]

Settings in IDE

• Module: [Generic ESP8266 Module|Nodemcu|]
• Flash Mode: [qio|dio|other]
• Flash Size: [4MB/1MB]
• lwip Variant: [v1.4|v2 Lower Memory|Higher Bandwidth]
• Reset Method: [ck|nodemcu]
• Flash Frequency: [40Mhz]
• CPU Frequency: [80Mhz|160MHz]
• Upload Using: [OTA|SERIAL]
• Upload Speed: [115200|other] (serial upload only)

Problem Description

configTime function (Time.c) supports timezone definition is given in seconds. But sntp_set_timezone(sint8 timezone) in sntp-lwip2.c requires time zone in hours. This is fault because there exsist other timezones then full hours also.

Please change sntp_set_timezone function to accept second based timezone, and validate zone using second values if(timezone >= -113600 || timezone <= 133600)

Dayligt savint time setup sntp_set_daylight(...) seems to use second values correctrly

MCVE Sketch

#include <Arduino.h>

void setup() {

// Setup Wifi connection

// Set TimeZone 5h 30min
int timeZoneH 5;
int timeZoneM 30;
	configTime((timeZoneH*60+timeZoneM)*60, 0, "pool.ntp.org", "time.nist.gov");
	time(nullptr);
}

void loop() {
		time_t now = time(nullptr);
		tm* t = localtime(&now);
// returned time is not in correct timezone 5h30min...

}

[oddstr13]

List of UTC time offsets

I would like to point out that a few are :45 off the full hour, and that historically there has been instances of higher precision than 15min, for example +01:24, +04:51 and -00:25:21 (second precision no less).
None of the odd non-15min increments are in use today as far as I can tell, but it would probably be best with at least minute precision for time zones.

[jyberg]

List of UTC time offsets

I would like to point out that a few are :45 off the full hour, and that historically there has been instances of higher precision than 15min, for example +01:24, +04:51 and -00:25:21 (second precision no less).
None of the odd non-15min increments are in use today as far as I can tell, but it would probably be best with at least minute precision for time zones.

yes that why I suggested to use seconds value like in configTime interface function uses and not convert to hours/minutes

[devyte]

Please test #5828 , it adds sntp_set_timezone_in_seconds(). You may have to
extern sntp_set_timezone_in_seconds(sint32 timezone);
at the top of your sketch, because the function signature isn't in a .h yet. Also, configTime() isn't updated either.