Trail offset to plotted position

johnonj Nov 17, 2016


For some reason, I am getting an offset between the trail position of Uranus and its plotted position of the planet's disc.

I set the trail to: Step 1 day, Index 1, Time Label Freq 15 days and Number of Steps 195. The start date is 1 Aug 2017 at 0 hrs UT. Round to nearest step was set to off.

Labels appear for 16 Aug; 31 Aug; 15 Sep; 30 Sep, 15 Oct; 30 Oct; 14 Nov; 29 Nov; 14 Dec; 29 Dec; 12 Jan; 27 Jan and 11 Feb.

I Noticed that there is only a 14 day (not a 15 day) gap between 29 Dec and 12 Jan.

When I set the date and time to 12 Jan 2018 at 0 hrs UT, Uranus was plotted on the Jan 11 tick on the trail.

Any help appreciated.