Garmin 60 'Sun and Moon' screen
I’ve discovered an issue with my Garmin GPS 60 CSx that I currently cannot find described anywhere else. It’s about the ‘Sun and Moon’ screen that shows you the sunrise and sunset information for a certain date and and a certain location on earth, on a day where DST changes the time at night.
The problem seems to be that the DST is not taken into account when the GPS calculates the sunset and sunrise time for that day. The local time that is shown on the GPS device however is displayed correctly, so the DST change by itself seems to be working correctly.
Let me explain by giving an example…
We set the date to Sunday 29-MAR-09 which is the day that Western Europe switches from winter-time to summer-time at Sunday night from 2 AM to 3 AM (01:59:59 to 03:00:00 to be exact). At Saturday 28th, at any time, the sunset for that day is given at 19:04, which is correct. At Sunday 29th the sunset indicated on the GPS at 03:00 should be 20:06, but it’s not.
The next table should give an overview.
| Location | Date/Time | Expected sunset time |
Actual sunset according to GPS |
| Amsterdam | Friday 27-MAR-2009 12:00 | 19:03 | 19:03 |
| Amsterdam | Saturday 28-MAR-2009 12:00 | 19:04 | 19:04 |
| Amsterdam | Saturday 28-MAR-2009 23:59 | 19:04 | 19:04 |
| Amsterdam | Sunday 29-MAR-2009 00:00 | 19:06 | 19:06 |
| Amsterdam | Sunday 29-MAR-2009 01:59 | 19:06 | 19:06 |
| Amsterdam | Sunday 29-MAR-2009 03:00 | 20:06 | 19:06 |
| Amsterdam | Sunday 29-MAR-2009 16:00 | 20:06 | 19:06 |
| Amsterdam | Monday 30-MAR-2009 00:00 | 20:08 | 20:08 |
It seems that the current time is not taken into account when the GPS calculates the sunset and sunrise times, but only the date. This is OK, but not for dates where the time changes.
Report the bug
Does anyone now how tot get a bug like this fixed with Garmin? I don’t want to explicitly contact their support because it is just a minor issue, though I think it would be nice if it would be fixed.
Conclusion
So if you happen to be trusting your GPS to tell you when the sun rises and set’s like I do, beware that the time may be one our off on days where the clock is set back or forward (mostly Sunday), depending on whether you use DST. I’ve seen this issue with the Garmin GPS 60CSx running the currently latest firmware (3.70).
Update 2009-05-24:
I submitted the bug with Garmin and got a response:
Thanks for your email I will be happy to help. This is a bug that we have come across before from another customer. It only seems to appear when the time zone on the unit is set for Amsterdam. If the unit is set to the London time zone the Sunset error doesn’t appear. We will pass your comments onto our software team in the USA as his is something that could be fixed in a future software update but I cant promise you that it will be.
Seems like there is a chance that it will be fixed!