Impossible.

I am working on a close earth-analog. History has progressed into a modern-equivalent age. For purposes of the answers, current earth may be assumed.

That's your basis and in this world there is no way that such a run of zero death would go unnoticed.

For a period of about two weeks; death stops. Everywhere, for all humans.

Accidents that would normally be fatal are no longer so

So every ER department and hospital will notice zero deaths for two weeks ! That alone would cause an instant investigation as to why. At the very least medical people would want to know how to keep making that happen.

I wonder if any major hospital has ever experienced a day with zero deaths.

But that ain't all.

Just a few people monitoring and watching closely will be insurance companies (believe me - they'll notice all the money it's not costing them - that they'll keep !), first responders ("Hey, that guy who was decapitated is still alive !"), the morgue ("That's the hundredth corpse that got up !") and the odd suicide case ("but seriously I used explosives - what do I have to do ?").

assassinations fail due to circumstance

Assassins don't just try and if the first attempt fails for unknown reasons they give up and go home. "Finish the Job" means everything in that business. They're going to notice because eventually they're going to try smashing someone's skull to pulp with a large blunt object and that's not going to fail expect in very, very, very, very ... you get the idea. The thing to remember about murder is that leaving a live witness is absolutely not what you will opt for. Try, try and try again is the order of the day.

The same, incidentally, must be said for the military. Military bosses tend to get very irritated when they send people to wipe out something else and it doesn't happen. Not happening continuously for two weeks ? At some point people are going to start pointing weapons directly at the people who "fail" and when that doesn't work ever, they will think how odd it is.

diseases are halted or are cured entirely

So the patient with dead kidneys, rotten liver and a completely dead brain is going to be cured and you expect no one to notice this happen the many times it will in a hospital ? In ICU life support is turned off and a clinically dead person just stays alive ? You think they won't notice this happen ?

And you think they won't be even more suspicious when death "turns on" again and for no apparent reason the same people spontaneously die ?

Medical people tend to be curious about little things like that.

, and all other methods of death either fail, are of lesser impact or otherwise resolve.

So even if you ignore all the terminal cases and murders that fail despite repeated attempts, there's no way hospitals, the police, administrators, insurance companies and all those myriad of organizations that not only can't avoid death but in some way exist to serve it (the word "undertaker" leaps to mind) won't notice a 100% drop in work.

Think of the hundreds of thousands of YouTube videos on all those mobile phones capturing all the miracle not deaths. No one will notice ?

They'll notice.

Yet, none of this is noticed either during this time or after death resumes.

And this is even less likely.

For decades, maybe even centuries, people would be curious about why no deaths occurred for two weeks. Think of all the relatively minor historical mysteries whose resolution can have no bearing on our lives but which some people are still researching. Humans love mysteries and people will certainly notice.

But it's even worse than that.

Not only would they notice it but people would, during that two weeks, start experimenting and trying not death-defying, but certain-death stunts in the "certain belief" they'd survive. This will happen a lot and then, suddenly people will start dying again. Whoops. People, even idiots daft enough to try these things (many YouTubers leap to mind) will spot that the magic no longer works - but not spot it for long.

And then people will really start asking questions.

So your idea is, if I may put it this way, a dead duck. Eventually. :-)

Any global supernatural force capable of neutralising death in all its forms should be equally capable of inducing amnesia about death itself. Therefore, no-one will notice that death has stopped happening.

In the case of morticians and funeral operators they will all believe they are on holiday from their usual occupations.

Obviously the agency responsible for the temporary cessation of death is capable of foiling the circumstances leading to mortality is both selective and exhibits intelligence. Therefore, as an adjunct to stopping death it should be able to influence brain function too. So, global selective amnesia about death is the obvious route to make death going on holiday go unnoticed.

I'm going to add to the "Not Possible" crowd but for reasons other than "undertakers."
Big Data. In the U.S. alone, you have Federal and state laws which mandate death statistics be collected, kept and analyzed. People are going to notice a periodic dip to 0 of fatalities because AI is going to chew through the statistics. Insurance companies are going to alter their business plans. Movie studios are going to attempt crazy stunts. Drug companies are going to do massive testing. The list can go on forever.

The best thing you could probably do then, is to turn this certainty of detection into a sub-plot. It could be serious in tone, or joking like Lois Lane being fooled by eyeglasses. It doesn't even need to be fleshed out completely, just enough to let the observer see that something is off and for whatever reason most people haven't noticed it, but he ones who have are exploiting it quietly. perhaps that creates danger for people who look too closely....

The people most likely to notice a lack of death would be morticians and funeral celebrants. Their business relies upon people dying, so people not dying should be noticed in their bottom line.

So how could it not be?

The question implies that an outside agency is preventing death, and is using non-obvious methods, but is also not concealing the lack of human mortality.

The nature of a business in the post-life industries is that mortality is unpredictable. Statistics will show that there is a predictable human mortality rate, however this mortality rate is only predictable over relatively long periods of time. On a day to day timeframe, a certain number of "customers" can be expected, but random factors can mean that those numbers can vary significantly on any particular day, from many times the usual daily number, down to none at all.

Perhaps just before the non-death period starts, there was an upturn in the numbers of deaths where the next of kin request embalming and other more expensive and time-consuming funeral options, so funerals wouldn't necessarily stop, as they would be delayed pending completion of the arrangements. This would still occur even without any upturn in expensive funerals, though to a lesser degree.
Funerals for suspicious deaths would also be delayed for a considerable amount of while the deaths were investigated.

So, workers in the funeral industry would no doubt notice a downturn in business, but it wouldn't outright cease. Perhaps the next of kin went to the competition...

Then, after the non-death period, there would likely be a large number of people who, instead of dying, 'merely' fell into a coma. If their lives were being sustained, it is reasonable to expect an upturn after the period. So... people weren't dying, but more would die afterwards, so the funeral industry members individual bottom lines wouldn't necessarily be greatly altered on a yearly or even on a monthly basis. "It was just a statistical blip".

Only if people around the world started comparing experiences might they begin to become suspicious, but the increased numbers deaths after the exemption period would tend to make the people most likely to question it too busy to take the time.

As for doctors and nurses, their business is saving lives. They would hardly question their good fortune if none of their patients died.

Although the global death rate is predictable, it's not when you look closely at a small town over a short period. The individuals concerned are used to days when nobody dies on their watch, and can't tell that it's happening to everyone else.

The bigger problem comes with the people who see the bigger picture, like the registrar or crematorium. Our local crematorium holds several funerals a day, booked half an hour apart with an hour off for lunch, but they have to schedule about 3 weeks ahead to get such a smooth flow. If people suddenly stopped dying, they'd have 3 weeks of bookings to work through before they ran out. For the first week they probably wouldn't notice anything because they'd be dealing with events from the previous week. In the second week the might notice, but they don't normally spend all day taking bookings. They've still got other tasks to keep them busy.

Even if they notice that they've recorded no deaths for a week, they don't know that it's happening everywhere else.

A month or two later, someone would collate the statistics for a wider area and they would notice that something unnatural had happened.

Impossible

Someone is going to jump off a very high building and survive. Some serial killer will decapitate a victim. Someone is going to go on a rampage with an AR15. Some car bomber is going to detonate in a crowded market.

All the miracle survival stories will pour out and into the media.

Reminds me of a story I read about an American newspaper that had on average ten obituaries per day. One day the lady who did them when on holiday and they had none placed for the two weeks she was away and when she returned, they went back to ten a day.

Not possible without some influence from whatever is preventing the deaths in the first place.

At Christmastime last year New York reported zero murders for six days in a row for the first time ever. A period of two weeks without deaths would be an internationally notable event even if it was restricted to murders in one city.

[Edit] I was thinking more about this. You could shorten the period significantly to like 1 hour and then this would work. The entire world could go without death for an hour and I don't think it would be immediately obvious, especially with your stipulation that people aren't unkillable, they would just not end up in situations where they would die.

As others pointed out: no, this is impossible. Not in our current world.

In order to make it possible, you have to change something. If you can somehow make people not care about the lack of death, then it could work. However, this has to be a VERY BIG change - not just trying to distract them, that won't work. You can't distract everybody and you can't occupy the attention of absolutely everybody for that long. You have to somehow make them have a complete blind spot in their mind for this phenomena. Here are some suggestions for how this could work:

• This is the realm of mind magic. Very, very powerful mind magic that affects the entire world. Some magician manages to just make every single person in the world turn a blind eye to otherwise miraculous survivals. A guy gets shot in the heart and walks away - onlookers should just shrug and go on their way.


• The sufficiently advanced technology equivalent is some sort of brainwash devices or waves. I can imagine satellites that can instantly brainwash the population.


• A slightly different approach is to consider "death" as metaphysical concept. Since it is eliminated (somehow), that doesn't just mean "nobody dies" but the whole idea of death is gone. The two are metaphysically linked, so not only can people not die, but now (for the next two weeks), nobody can even conceive of death. It's as if that was never a thing.

These approaches still leave gaps but somehow, these also need to be covered up by whatever method affects the people. For example:

• there would still be graveyards - the previously dead would stay dead, after all. It seems odd that nobody can die and yet there are these dead people there from before.


• Weapons that cause death of individuals like pistols are now mostly useless. These are wide-spread but...now they don't have a reason to exist.


• There are people who directly build their business dealing with the dead. For example, undertakers. Without death, why would they exist?

My personal idea is to half-acknowledge these but still turn a blind eye to them. After all, every single person somehow forgets death existed, it's not too much of a stretch to also have them engage in some doublethink. People can still go and visit the graves of their relatives and keep a gun around even though they know nobody can die. Undertakers might go to work every day and lament the lack of clients even though they simply cannot have clients.

A slight alternative is for the clashing ideas to manifest in some (possibly odd) justifications that people come up with due to the cognitive dissonance. They will know of graves but might forget that there are dead people in them. They could still go visit but as more of a habit. They'd know it's something about paying their respects to aunt Alice and uncle Bob but somehow don't make the mental connection that they are dead. A gun might find unorthodox uses - opening jars, or more extremely - as "toy" for children to play tag with. Undertakers might go and take care of the graves - they don't have anything else to do right now and that's sort of what they did before. They can go and tend to the "memorials" that definitely-don't-have-dead-people and have them nice and clean.

The utter inconceivability of death does require more changes than simply reconciling it with the existence of death before. The thinking of people needs to change and people should reconsider the intend to kill

• if the military wants to do an operation against an enemy force it would be weird to expect shooting to get them anywhere.
  
  
  • Maybe they alter their plans to just blow up key structures - doesn't need to be "non-lethal", perhaps burying the enemies alive is accepted and expected. It is, after all, now the only way to incapacitate an enemy.
  
  


• criminals that wants to take out a target by shooting or stabbing them would be strange
  
  
  • Instead the criminals might resort to torture or blackmail.
  
  
  • In extreme cases, the old "bury a body in cement" or "let them sleep with the fishes" still works - the target is silenced, even if alive.
  
  


• trying to eliminate somebody for inheritance or other sort of gain would similarly undergo a change.
  
  
  • ...OK, I thought to bring up the point but I've been racking my brain and can't think of a good alternative. Not without resulting with basically the same as "criminals" and dropping the rich uncle into concrete. But without death, that's not going to net you inheritance. Not to mention that "inheritance" would also not work, unless the cognitive dissonance somehow makes people enact that if a person is "missing".
  
  

When death comes back, so should the knowledge of it. It could be very jarring, however, if eliminating death also made people forget it, then perhaps reintroducing death also "magically" makes them immediately know the concept and not notice the difference. Not at first. This way you could have a more of a slow burn for the realisation. It might be a day or two until somebody notices and even then it might not immediately be noticed around the world. It could start with somebody going to the fridge for a pickle and suddenly thinking "Wait, Why did I use a gun to open this jar of pickles, I could have killed somebody". That doesn't immediately cause the discrepancy to be noticed but people will gradually start remembering acting differently for those two weeks without some discernable reason. Eventually, somebody is going to figure it out and connect some dots that nobody died, however that gives you more leeway for the reveal, not everybody suddenly going "WHY DIDN'T ANYBODY DIE" the second the two weeks run out.

Just make people feel like they don't want to kill anybody during those two weeks.

As others have mentioned, while it's still possible that the lack of natural deaths or accidents goes unnoticed because of statistics perks, it's very likely that a living person with a totally smashed skull attracts the attention of the crowd.

So why not make that during those two weeks people don't have the desire to kill anyone, or have a very weak desire to do so?

All of a sudden, generals in war order a "fortnight period to study enemy's positions" instead of attacking. Missile launches are put off or canceled in order to verify some technical issues once more. Assassins who don't succeed at the first attempt are ordered to withdraw and wait for a more favourable moment. Would-have-been murderers just stop a bit and reflect about their life and find a better way to solve their ongoing situation. And so on.

This goes unnoticed because all those people simply genuinely want to do something else. Those who kill people professionally still want to do their job, just later. It's not that they don't want to accomplish their mission, it's that there's something more urgent to do now.

You're going to need to cut off communications and drive people apart. I suggest a mega typhoon. Or maybe a whole set of them. Storms across the globe of epic intensity such that no one is really communicating, and they're all just grateful that their little corner of the world is wet but no one is dead. They can compare notes when the sun comes out.

You basically have a patch that will stop people from dying.

The basic test is to intentinally kill someone.
In 2002, the statistic was one murder every 60 sec. Human have been testing your patch since the beginning of time. And scaled up into a stress test. People will notice. Most of the South America are currently trying to ddos, stress test and pen test the new rule.

Drug cartel, gouv, terrorist, military will notice.
And will come up with new test. And try to find limitation.

In advanced countries with bureaucracies that rule most of the people on the planet, all deaths are supposed to be reported to official statistical bureaus. Depending on the average number of death reported per day to a specific organization, it may take days, hours, or minutes for someone to notice a big drop in reported deaths, and if they try contacting people to see why they are suddenly slow to report and learn that there are no deaths to report so far that will be news.