Comic book readers have respectively different reading speed and this means that time in comics is translated by readers` view. The authors arrange panels and gutters to control time, but time recognition in comics depends on the readers and generally it is the readers` role. On the contrary, the phenomenon having occurred by infinite canvas varied the authority of timing. Infinite canvas can give the comic book authors more authority of controlling timing than the readers by intervening in readers` relative time as an agents and transforming their fictive time into absolute time. Following to the concept of "Agency" in games, agency is the power which satisfies the players by reemergence of their intentions. Since some of digital comics absorbed the properties of other media such as animation and sound, we can see that the reader`s timing agency is shifted to the author`s timing agency. The purpose of this study is to analyse this phenomenon and to remind that agency motivated by the balance between material constraints and formal constraints becomes a condition of readability of digital comics but excessive timing constraints given to the readers causes a decrease of the readers` timing agency. This also can be a considerable matter when we produce digital comics.