Transfer Window Planner / Kerbal Alarm Clock: Modded vs Stock

[DVQuill]

So out of curiosity, I did a quick comparison of the stock Transfer Window Planner (TWP) and Kerbal Alarm Clock (KAC) implemented in 1.12, against the modded versions of the tools (also by TriggerAu). I figured some of you might be interested in the information, so I figured I would share. 

As expected, there is very little difference in the TWP tool from stock to modded. Granted, the modded version provides a bit more information and flexibility, but its great news to see the numbers line up. 

The KAC tool on the other hand, provided much more interesting results. While the modded version of the alarm tool provides a transfer window to Duna that matches those provided by the TWP tools, the stock version of KAC gave a departure date which was about 20-25 days sooner. Hmmm...

It's hard to tell what this means, given that we don't know if the tool has a preference for travel time or dV, but it stood out as being quite different when compared to the other 3 tools. What do you guys think could account for the departure date difference here?