One example of people doing something at the exact same time (there are countless example as it is quite common), is Super Bowl, around 50% of the USA population watched that, then there is Christmas that is sort of synchronised, in Sweden almost every single person would tune into "Kalle Anka" at the exact same time, coordinated activity. Those are massive populations, all in sync, managing somehow, so it is provably not that impossible at all, nor necessarily impractical. You have coordinated activity, people doing things in sync, always, that is nothing new, so, not a problem, no impossibility. The nation-state strawman is highly impractical, it limits cognitive potential and makes people dumb conformists, sheep, so much more practical with a pseudo-anonymous personhood. I would probably do the monthly events, minimal work, and good pay (mining rewards from proof-of-power is part of that. ) Have done a lot more shittier work in my life, seems like a good deal.
Overall, getting people to do something at the exact same time, coordination, that is what "the economy" has always done. Money, as an incentive, a scarce resources, that everyone conforms to, that isn't new, it has always worked, people go to work on time every day, so game theoretically it is in no way impossible to get people to do something at the exact same time, that has already been achieved before, there is historical precedent.