What do <onDays> and <offDays> parameters do in Storytellets files?

[Hjkma]

I want to increase the frequency of world quests. Here is a xml file snippet

<li Class="StorytellerCompProperties_OnOffCycle">
        <category>WorldQuest</category>
        <allowedTargetTags>
          <li>World</li>
        </allowedTargetTags>
        <onDays>15</onDays>
        <minSpacingDays>0.2</minSpacingDays>
        <numIncidentsRange>2</numIncidentsRange>
        <acceptFractionByDaysPassedCurve>
          <points>
            <li>(5, 0)</li>
            <li>(30, 1)</li>
          </points>
        </acceptFractionByDaysPassedCurve>
      </li>

I can not understand what the following parameter means

<onDays>15</onDays>

What does it do? And in other places in the file there is a parameter

<offDays>8</offDays>

Can someone clarify the values of the parameters or throw a link to the explanation?

[LWM]

I glanced at the code out of curiosity.

onDays seems to mean "up to what day can this even happen?" when the event generator is calculating events.

High "offDays" seems to lower the chance of the events happening?

Good luck!