Acid‐autocatalyzed clock reactions are chemical systems able to suddenly lower pH after a certain time. They would be useful to program self‐assembly of pH‐responsive building blocks if factors such as the starting pH, the magnitude and time of pH decrease could be flexibly tailored. Here, we show how to control these parameters in the chlorite‐tetrathionate (CT) clock reaction using cyclic esters, such as δ‐gluconolactone (GL) and 1,3‐propanesultone (PrS), as in situ slow acid generators.