Conecpt for Daylightsavingtime

[holgerlembke]

Just and idea for a somehow flexible daylightsavingtime implementation.

works for my German case.

[Apollon77]

Hey, I use the "Timezone" library additionally to Time (https://github.com/JChristensen/Timezone) and it works great. Just some lines of code

[timo-keller]

Hey,

I think there might be a problem with the DST provider in your example code:
TimeLib defines sunday as dow 1: uint8_t Wday; // day of week, sunday is day 1,
whereas your example code expects sunday to be weekday 0: #define FIRSTDAY 6 // 0 = Sunday according to the referenced source.

[terryjmyers]

I've successfully implemented DST in this routine. I did this recently with a direct fork from a few weeks ago:
https://github.com/terryjmyers/TimeLib

EDIT: OMG!! I've tried to paste some code snippets here like 100 times...I friggin give up, here is the meat and potatoes routine(completely unformatted because the <> button doesn't seem to like it...(just go to my git above and look at the changes...sheesh
bool isDST(tmElements_t &tm){ //adapted from http://stackoverflow.com/questions/5590429/calculating-daylight-saving-time-from-only-date if (dstRule == 0) return false; int previousSunday = tm.Day - tm.Wday; if (dstRule == 1) { //January, february, and december are out. if (tm.Month < 3 || tm.Month > 11) { return false; } //April to October are in if (tm.Month > 3 && tm.Month < 11) { return true; } //In march, we are DST if our previous sunday was on or after the 8th. if (tm.Month == 3) { return previousSunday >= 8; } //In november we must be before the first sunday to be dst. //That means the previous sunday must be before the 1st. return previousSunday <= 0; } else if (dstRule == 2) { if (tm.Month < 3 || tm.Month > 10) return false; if (tm.Month > 3 && tm.Month < 10) return true; if (tm.Month == 3) return previousSunday >= 25; if (tm.Month == 10) return previousSunday < 25; return false; // this line never gonna happend } }