Disposition Gain for Remaining Summoned?

After the second day of keeping watch on this passive disposition gain, I can confirm that the increase occurs only by keeping them summoned in one session as opposed to being based on how much summoning time was used overall in the day. Summoning her during the afternoon for about 10-20 minutes, desummoning her, and then summoning her again later at the midnight to see how it would affect the increases resulted at around 90 min. summoning time remaining and around 40 min. summoning time remaining.

Another session timing the increases should be enough to warrant adding it to the table, unless someone else comes in before I do so saying this isn't intentional.