I made a GPS controlled clock with time and date. The time is UTC. Now, if I want the clock show local time in, say, time zone +2, I will add 2 hours to the time (and correct if it passes 24). However, that means that the date changes 2 hours late relative to local midnight. I have to also correc…

You could look at how the DateTime and TimeSpan classes in the RTClib library handle it. You could even just use those classes. [image] GitHub - adafruit/RTClib: A fork of Jeelab's fantastic RTC Arduino library A fork of Jeelab's fantastic RTC Arduino library. Contribute to adafruit/RTC…

[image] nfoldager: Is there a smarter way to do it? Which Arduino board?

[image] nfoldager: Is there a smarter way to do it? Use the Arduino TimeLib.h (Time) library to do the conversion.

This function might be useful to you: byte days_in_month (int y, byte m) { // Fourth, eleventh, ninth, and sixth, // thirty days to each we fix. if ((m==4)||(m==11)||(m==9)||(m==6)) return 30; // Every other, thirty-one, // except the second month alone, if (m!=2) return 31; // whic…

[image] nfoldager: However, that means that the date changes 2 hours late relative to local midnight. I have to also correct the date. your time zone adjustment should not only change the hour but should take the UTC timestamp / epoche, add 2h (or 1h during DST) and take the new timestamp a…

@all of you Thank you for your replies. I Appreciate it. It will take me some time to study your suggestions. @noiasca : Arduino Uno. your time zone adjustment should not only change the hour Exactly. Usually, I would use the Julian day conversion/back conversion for that, but it seems clumsy…

[image] nfoldager: What do you suggest? it seems TinyGPSPlus doesn't have a interface to get a timestamp/epoche (just an assumption, one can proof me wrong). I would collect the time/date parts and hand over it to either time.h or the TimeLib.h and then let either one of these calculate the …

@noiasca : Thank you so much for that code. I'm sure this is the way to go. And I get some insight in time.h. Best regards, Niels

[image] nfoldager: Usually, I would use the Julian day conversion/back conversion for that, but it seems clumsy here, Unix time and the Time library use seconds since a particular epoch (e.g. midnight before Jan.1, 1970 = 0). To subtract an hour, just subtract 3600 seconds, and convert to dat…

[image] nfoldager: Is there a smarter way to do it? There is, it’s been suggested in several replies. The PJRC time (aka TimeLib) library can do a lot more than has already mentioned. It will keep time internally using the millis counter and you can specify callback a function to be periodica…

GPS/UTC: Calender problem in time zone <> 0 - Solved

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van_der_decken March 2, 2024, 5:54pm 2

You could look at how the DateTime and TimeSpan classes in the RTClib library handle it. You could even just use those classes.

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GPS/UTC: Calender problem in time zone <> 0 - Solved

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