Greetings,
I'm not really sure if this is a bug report or an unfortunate side effect of using daylength, not really noticed this till I started playing with the value at 7 and 14. The values for "running cost" shown in the purchase/train information windows remain fixed, while the actual running cost and "train running costs" in the finances window differ. It appears that daylength either scales actual running cost up or down, making a game harder or easier - but the expected running cost remains the same.
A quick test shows that you get the following results, which make even less sense to me;
Daylength 1 = Actual: 878 / Displayed: 878 (x1)
Daylength 3 = Actual: 2525 / Displayed: 841 (x3)
Daylength 5 = Actual: 1286 / Displayed: 832 (x1.54)
Daylength 7 = Actual: 66 / Displayed: 825 (x0.07)
Is this strange behaviour to be expected, is it a bug or is there a way to keep all the running costs values the same I am missing?
EDIT: Added some savegames, might help anybody that wants to observe in-game.