BigTimer node question - Sunset message confusion

I am using the BigTimer node and have noticed something of interest (to me).

Back story.
Daily at sunset I get a message indicating sunset.
After a delay my clock notifies me. Ok, that time is not specifically SUNSET, but it does track the months and you can see the trend.
(Oh, I am in Sydney OZ)

June 21 is the shortest day of the year. I'll give a day or so either way.

So, this month I've seen this signal happening and it is slowly creeping past 18:00 (local) to 18:01, 02, 03, and so on.
On 21'st June it happened at 18:11/2. Again I'm not too fussed with second precision as I only see HH:mm on the clock.

So: 18:12 (call it) is the shortest day of the year.... Days after that get longer. IE: Sun rises sooner and sets later.

So why is it today (28 June) the signal is happening at 18:14?

I'm confused.
Someone - please?
I've asked someone (via phone) who is into the planets and stuff and they couldn't answer me.
I'm asking here not to put you on the spot but because here, the people understand what/how that node works (no blame intended) and may have a better understanding of what is going on.


Not necessarily. After the shortest day the sun may still rise later, but set even more later, so the day is longer. Look up the times of your local sunrise/sunset to check before assuming it is a node-red issue. Also check at what time you are getting the signal from the bigtimer node so you can compare them directly with what they should be. Use a debug node configured to output to the console then it will go to syslog so you can check it later. You can't submit an issue against the node because it does not have a github (or similar) repository, or at least it didn't, which is one of the reasons I don't use it.

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I wasn't saying it was a node-red issue.

I asked someone who knows about the planets and that stuff, but over the phone they didn't understand the question.

Maybe I can't talk.... (Dunno)
I was asking here as the people here know how things work and as they wrote the code to make the node to give sunset times they would understand the maths also.
So asking here it is better in a lot of ways.

To use the debug node as you say it will take another.... 360 days for it to happen again.
I don't know how to fake dates into such nodes.

Chron Plus would/could give the same values... But for the shortest day.... It is 6 days behind me now.
Again: I can't test the two to compare them for that.
I could see if they both give the same sunset time, but that isn't exactly what I was asking.

Maybe some useful graphs/numbers here to help compare - Sunrise and sunset times in Sydney

There are various implementations of the sunrise calculations and various nodes use different libraries. they are all approximations.

for your case, there is about 1m difference in daylight duration from 21st ~ 28th however, both the sunrise AND the sunset time have moved...


Source: Sunrise and sunset times in Sydney

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Neither was I, you seem to have ignored my suggestion

But I see others have done it for you.

So given all this information - and sorry I didn't look at the table (or even get it) before asking - these 8 days are in a bit of flux to their times and so this is not unusual.

It was only a couple of minutes difference (ok, 2.... but that's a couple) it is normal.

I am now blushing.

I had never noticed this before, as much as I try to keep my eyes open.
I guess the last couple of years with things I haven't been in front of the display at that specific time and noticed it.

Greatest apologies if it is seen as Crying wolf.
I just didn't understand the mechanics of what was happening in the bigger picture.



You might find this useful in explaining why this happens

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Thanks very much for that.

I've started reading it but all those big words it will take some time to process and understand.

(But seriously: Thanks. I was suspicious of something like that but just didn't get it.)

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