Discrepancy between KER and BBT geostationary orbits

[Apocalyptapig]

So, I use (among other mods) Kerbal Engineer Redux and Better Burn Time. A few days ago, I set up a keostationary tri-satellite constellation, using KER to get my orbital period down to pretty much exactly 1 day (give or take a few milliseconds). Yesterday, I installed BBT, and noticed that it said I was 50s off from perfect keosync. But my orbital period is exactly the same as a Kerbin day, right? So, which one is more accurate here - BBT or KER?

 

[Stone Blue]

1 hour ago, Apocalyptapig said:

So, I use (among other mods) Kerbal Engineer Redux and Better Burn Time. A few days ago, I set up a keostationary tri-satellite constellation, using KER to get my orbital period down to pretty much exactly 1 day (give or take a few milliseconds). Yesterday, I installed BBT, and noticed that it said I was 50s off from perfect keosync. But my orbital period is exactly the same as a Kerbin day, right? So, which one is more accurate here - BBT or KER?

 

I could be wrong, but I thin you would need to do a side-by-side comparison...
KSP orbits are not held perfectly for long... drift is added, and starts racing up, pretty much right after you set an orbit...
I used to try to get my relay constellations perfect, within milliseconds... but even on tiny, 7 part sats, I found that even using ONLY reaction wheels to reorient the craft in-place, would introduce immediate, and significant changes, when you are talking seconds or less

[Apocalyptapig]

41 minutes ago, Stone Blue said:

I could be wrong, but I thin you would need to do a side-by-side comparison...
KSP orbits are not held perfectly for long... drift is added, and starts racing up, pretty much right after you set an orbit...
I used to try to get my relay constellations perfect, within milliseconds... but even on tiny, 7 part sats, I found that even using ONLY reaction wheels to reorient the craft in-place, would introduce immediate, and significant changes, when you are talking seconds or less

That's right, but my problem is that two separate tools are giving two separate readouts, about a minute apart, not orbital drift. To rephrase my question, is keosynchronous orbit an orbital period of 1 kerbin day, or 1 kerbin day - 50 seconds, as BBT tells me?

Edit: and yeah, shooting for exact orbits isn't really gonna help, but I also have BetterTimeWarp installed, and since I use ion engines on these probes, I can get pretty precise orbital periods, like down to hundredths of a second.

Edited November 7, 2020 by Apocalyptapig

[Stone Blue]

Ok.. your initial question made it sound lie you noted KER data a few days ago, *then* installed BBT, and compared *its* data to old KER data

idk... but mebbe this helps? vOv

https://wiki.kerbalspaceprogram.com/wiki/KEO

[Apocalyptapig]

4 minutes ago, Stone Blue said:

Ok.. your initial question made it sound lie you noted KER data a few days ago, *then* installed BBT, and compared *its* data to old KER data

idk... but mebbe this helps? vOv

https://wiki.kerbalspaceprogram.com/wiki/KEO

Oops, yeah; I was awfully unclear with that first statement. Thanks for linking that wiki article btw, it's exactly what I needed to see :D. So, it appears that BBT is about 50s off in its KEO calculations. Well, that's weird, but I can live with it.