Wrong time in Netherlands #167

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1. mourner commented on Jun 18, 2026

   

   mourner

   on Jun 18, 2026

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   DST is actually handled correctly here — the issue is comparing across timezone boundaries. SunCalc returns UTC instants; once you format each in its own zone (which applies summer/winter time automatically), everything lines up:

               UTC      local
   Birmingham  03:44 →  04:44  (BST,  UTC+1)
   Amsterdam   03:17 →  05:17  (CEST, UTC+2)
   Hamburg     02:50 →  04:50  (CEST, UTC+2)
   

   In UTC the times are strictly monotonic west→east, as they must be. The reason Amsterdam's local sunrise is later than Hamburg's is that both are in the same timezone (CEST), but Amsterdam is ~5° further west — so by the clock the sun rises later there. Birmingham only looks earlier because the UK clock is one hour behind. So the "Amsterdam should fall between Birmingham and Hamburg" expectation is what's off; it's a timezone artifact, not a calculation error.

   const sr = SunCalc.getTimes(date, 52.37, 4.90).sunrise;
   sr.toLocaleTimeString('nl-NL', { timeZone: 'Europe/Amsterdam' }); // DST applied automatically

   Closing as a timezone/display matter rather than a bug.
2. mourner

   closed this as completedon Jun 18, 2026