Sunrise/Sunset Time incorrect

Am not really sure - I know that there's an equation of time that can be easily implemented in any device that calculates sunset/sunrise times based on time and position (that's all you need to know - where you are on the globe and what date it is). Am reasonably sure Garmin does it this way (in another thread I've been trying to troubleshoot something else so played with the widget). In any case, the difference is really minute and simply suggests minor location details (as mentioned, the equation of time gives you the info. you need, so if your reference is from some website it may simply have a slightly different coordinates as a reference than where your watch thinks you are). If you want to be sure, go into the widget,  press menu, then change the location by entering some slightly different coordinates (dunno the centre of the city where you are or...) and see how the sunrise/sunset times change a bit by just entering marginally different locations...

Am not really sure - I know that there's an equation of time that can be easily implemented in any device that calculates sunset/sunrise times based on time and position (that's all you need to know - where you are on the globe and what date it is). Am reasonably sure Garmin does it this way (in another thread I've been trying to troubleshoot something else so played with the widget). In any case, the difference is really minute and simply suggests minor location details (as mentioned, the equation of time gives you the info. you need, so if your reference is from some website it may simply have a slightly different coordinates as a reference than where your watch thinks you are). If you want to be sure, go into the widget,  press menu, then change the location by entering some slightly different coordinates (dunno the centre of the city where you are or...) and see how the sunrise/sunset times change a bit by just entering marginally different locations...

I checked the times with the exact coordinates and altitude on the website you linked.
The times then come exactly as I have described. So the Instinct Solar is not exactly right.
The Instinct Solar deviates by 4 minutes.
That is of course not much, but with that the Instinct Solar is about 3 days behind in terms of the correct times for the sunrise and sunset.

Skyliner said:

The Instinct Solar deviates by 4 minutes.

Strange, my Instinct is accurate to the minute. Make sure you use the same coordinates and the same altitude Garmin Instinct shows - go out and long-press the GPS button to aquire the position, and wait a few minutes. Re-check the sunrise/sunset times on the display. Calibrate the altimeter. If you are in a building a few meters above the surface, do not forget adjusting the altitude accordingly. Try the online calculator also for 0 elevation, just to see which variant is closer to the one Instinct shows.

I'm guessing that the watch uses the last GPS location to calculate this, so if that's not the  as the other source for rise/set you're using the times will be off by a small bit.

Maybe try running something that uses GPS and see if it corrects/changes. 

jim_m_58 said:

Maybe try running something that uses GPS and see if it corrects/changes.

Long-pressing the GPS button, as I wrote, is sufficient, for acquirng the current position. In the same time it shows you the exact coordinates, and the altitude you should use for the calculation

I've already tried it with GPS, but it hasn't changed anything. I'm still trying to calibrate the altimeter.
If that doesn't change anything, then I'll just live with the imprecise times.
Many thanks for your help.

I have now used various options to calibrate the altimeter.
No matter which altitude is then calibrated, the times for sunrise and sunset do not change at all.

My Instinct Solar Tactical does the same... I have to set hour by GPS to display the correct sunrise/sunset time. But after 1 or 2 days does decalibrate again...