To all the citizens of France and to all the people who are sure to find themselves in proximity of Ile de France on the afternoon of Saturday, 11th of September, 2021.

I am aware that introducing myself as a "conspiracy theorist" will rightfully cause skepticism in the readers, but I would also like to state how fruitful the reduction of the core of a question of predictability of modern-day events on the basis of analogical thinking to a purely logical system can be.
That is the case with leaving behind all numerological drivel concerning the selection of selected dates, times and places as a stage for a classified event that a "sufficiently powerful hidden agent" may want to cast on the public scene with mathematical punctuality or withhold at will until an arbitrary desired prerequisite is met.
Essentially, one may just look at the recent history of terrorism on European soil and identify analogies which are sure to be reproduced by any future successive step in the sequence of attacks, defining the time and date for a similar event in a span of time that is likely to constitute a turning point in the relevant general history (such as, clearly, the 20th anniversary of the 9/11 attacks), and defining whether the place will be the same as that of any other event on the list or not, depending on how similar the scheme describing the date and time of the attack that they are trying to predict and those of attacks that have already occurred are.