If the Game Master feels like a certain event should fill or erase sections of a Clock (even if that event is not tied to a Check), they are free to fill or erase one section, or two sections for a major event.
On the other end of that, some of the characters' choices might automatically fill a Clock or make it completely useless — for instance, smashing the Crystal of Life to pieces will make the "channel the power of the Crystal" Clock irrelevant.
The Game Master is responsible for discarding Clocks that no longer matter within the story, provided this doesn't strip the Player Characters of the ability to shape the story.
The next section details the rules for conflict scenes — chases, battles, audiences, and more! These scenes will see characters working against each other to achieve goals, and Clocks are an excellent way to keep track of everyone's progress, as explained under the Objective action (page 72).
Example: During a duel between the two rivals Bertrand and Duma, the Game Master assigns each participant a six-section Clock. The first challenger to complete their Clock will win the duel.
The Game Master should also employ Clocks to signal that the heroes have a limited amount of time to stop an antagonist's plans, obtain a specific item, or learn information. In short, Clocks should be used to convey pressure and keep the tension high — seeing how much time is left, the heroes will be able to manage their resources appropriately and should feel like every action is impactful.
Example: The Obliterator Airship Babel will be operative within four days. If they want to neutralize its soul core and prevent the Emperor from conquering the region, the heroes have no time to lose!
The Game Master draws a huge Clock on the world map — four sections only! Clocks like these are "time trackers" and normally can't be directly influenced through Checks — they should be the focus of one or more sessions.