Bill Watterson is a bit of a slow adopter when it comes to technology, and he reflects that in his characters. That, combined with some of the biggest technological paradigm shifts of our time happening right after the strip ended, results in a lot of Calvin and Hobbes visibly showing its age.
- Overall, the biggest and most major example is the fact the strip ended right before the Internet and cellphones massively took off in the late 90s, rapidly and radically changing global culture on a scale few predicted. The strip is a time capsule where Calvin's only forms of entertainment are watching television or going outside to make his own fun (the strip's seemingly intentional ignorance of video games notwithstanding), and it was still possible for him to be almost totally isolated from the world outside his neighborhood. Many jokes and stories only work because cellphones and the Internet as we now know it didn't exist at the time or weren't ubiquitous as they became in the years after the strip ended (many of which are noted in more detail below).
- The arc where Calvin locks Rosalyn out of the house would have gone differently these days due to the availability of cell phones. Rosalyn could easily have called Calvin's parents and explained the situation or at the very least threatened to do so if Calvin didn't let her back inside. It could still have worked if she had left her cell phone inside before Calvin locked her out, but it would at least have had to be accounted for.
- A Running Gag in the Rosalyn storylines is that she spends most of her time on the phone with her boyfriend — specifically the house's land line, which Calvin occasionally uses to mess with her. Nowadays, she'd be calling her boyfriend (or, even more likely, texting him) on her personal cell phone, shielding her from such shenanigans.
- In two Rosalyn arcs, Calvin's mom gripes about the time she spends on the phone looking for babysitters (an hour in the former and a week in the latter). These days, she can find someone to watch over Calvin online or with an app on her cell phone in a fraction of the time.
- In a few strips, Calvin uses a payphone to call home (and in one babysitting arc, Calvin's mom uses one). Nowadays, payphones are far less common in the United States than they would've been in the 80s or 90s (in 1995 there were about 2.6 million of them in the US, but by 2018 that number had shrunk to about 100 000), because, once again, nearly everyone now carries around a cellphone, which now nearly every kid would use over a payphone.
- The story arc where Calvin gets lost at the zoo would be over a lot quicker if Calvin had been (say it with us now) carrying a cellphone.
- The Sunday strip
where Calvin attempts to prove to his dad that Hobbes pounces on him when he comes home by taking a picture, and the story arc where he goes back to the Jurassic to take photos of dinosaurs would also be far more easily credible if Calvin had (you guessed it!) a cellphone that could take video, as is commonplace nowadays (in the aforementioned Sunday strip, Calvin says he needs to get a video camera, but those have generally been replaced with smartphones in general use). - Calvin references that if they want to rent a movie, they need to rent a VCR to go with it, or watch a matinee. He and Hobbes only manage to do that in one strip, the one time his parents leave him alone for the night. In the 2020s, they could just log onto a streaming service with an Internet connection. Of course, Dad is notoriously anti-tech and balks at the thought of even getting a computer. However, he did have one a few strips late in the comic's run, likely since his work requires that.
- In one 1995 comic, Calvin asks his dad why their computer doesn't have online service. It's justified at the time because his dad is a bit of a luddite. By the end of the decade, having a computer but not having Internet became virtually unheard of due to rapid commercialization and website growth, and increasingly faster dial-up speed greatly increasing its usefulness and ease of use by the general public.
- The strip ended just as the personal computer market was really taking off (and long before social media was a thing), so that computers are only mentioned a small handful of times, while focusing the vast majority of its technological criticism at television instead. By the early 2010s, computers had basically supplanted television as the primary means of home entertainment, particularly since smartphones and smart televisions incorporate features of computers into them, and streaming services which allow most tv shows to be watched on your computer.
- The video game industry took off a few years after the strip was first published, but the medium is never mentioned once in the comic. Even though it's perfectly in-character for his dad to disallow such things, it's also rather odd that Calvin, who's shown plenty of love towards comic books and cartoons, is never once shown going to an arcade or ever asking his parents for a console or games for their family computer.
- One strip has Calvin's parents argue over whether they should buy an answering machine. These days, when most phones come with built-in message-taking systems, there'd probably be no such argument.
- A number of strips show one of Calvin's parents waiting for someone to call them, only for Calvin to disrupt the call or hang up. Aside from the aforementioned fact that most phones these days automatically have an answering machine, most people could communicate through a personal cellphone or by email nowadays.
- Several strips show Calvin's mom writing up letters with a typewriter (and in one strip Hobbes refers to carbon paper). By the 1990s, typewriters had been rendered obsolete by writing programs in personal computers, and carbon paper as common household stationary vanished with it.
- In one strip, Calvin's dad mentions car phones among other new technologies. Car phones ended up being a relatively short-lived fad, since the now-ubiquitous nature of cellphones and Bluetooth devices that could wirelessly hook up the phone's functions to the car made them largely pointless, as did laws against phone-use while driving. Car phones became virtually extinct by the late 2000s.
- In the same strip, Calvin's dad also mentions fax machines among the newer technology. While faxes do technically still exist, their name is often considered synonymous with technology that's archaic and obsolete, and are far less common nowadays, since they've been rendered basically redundant by the Internet and email in the 21st century (although they remain popular in the healthcare industry and in Japan).
- In a different strip, Calvin bemoans that their car doesn't even have a cassette deck. Cars with built-in cassette decks declined near the end of the 90s, and stopped entirely by 2010, replaced by CD players or Bluetooth devices that could connect music in your phone to the car.
- Several strips center around Calvin wasting a roll of camera film either by refusing to sit still for a good picture taken by his dad or taking pictures of frivolous objects. By the late 1990s, film photography was dying out, replaced by digital cameras and cellphones with cameras built-in that can take a practically limitless amount of photos. In one strip, Calvin's dad mentions Kodak, a photography company that declared bankruptcy in 2012 in large part due to its stubbornness to transition from film to digital.
- In one 1992 strip, Calvin complains to his dad how their house not having cable television means they can't keep up with national cultural homogeny. When his dad says there's still McDonald's and Walmart, Calvin replies that those don't come into peoples' homes. Now with the Internet and online home delivery services, they can!
- The few times when we see Calvin's dad on the computer, it's using a blocky CRT monitor and has the monitor mounted on a horizontal PC case. Most modern computers passed the mid 2000s are much slimmer LCD or OLED models and the popularity of desk-mounted horizontal PCs has been replaced by vertical "tower" PCs placed on the floor.
- Numerous jokes about Calvin calling the library or the hardware store to ask them about obscene things or weaponry, only to be told off by the employee on the other end, are dated now because Calvin could easily look them up on the Internet without needing to contact anyone.
- The Running Gag about Calvin obsessing over his chewing gum specialist magazine is a bit dated nowadays, since obsession over magazine opinion pieces has changed from opinion piece articles and blogs on the Internet. For example, one 1993 strip has Calvin doing a magazine quiz titled "Does your gum deliver? 10 questions show what you could be missing!", which would almost certainly be recycled into the far more common Internet quizzes nowadays.
- In one 1993 strip, Calvin muses about the coming "electronic superhighway" that will link phones, computers, and televisions together for instant, interactive personal information. By the late 2000s, the attributes of computers, phones (in the form of smartphones), and televisions being linked together had basically happened.
- Several strips had Calvin listening to music on a phonographic record or on the radio. Even at the time, CDs were gaining popularity, and were eventually replaced by digital audio players such as MP3 players, smartphones, and wireless speakers that could connect to them by the 2000s. That said, vinyl records made a resurgence in the early 2010s, so it's still plausible for Calvin's family to have a record player, especially someone like Calvin's dad who has a preference for more archaic devices.
- In the story arc where Calvin is trying to build a robot, he records his voice with a cassette player with the intentions to put it into the robot, while in another story arc he uses one to trick Susie into a closet with a recording of his voice. Nowadays, most kids could just use their cellphone to record their voice.
- The rotary telephone and antennae television, which were already intentionally anachronistic in the 1980s, would now be considered ridiculously out-of-date by the 21st century when home phones mostly became wireless by the end of the 2000s and development of large, flat-screen televisions in the late 1990s which have since displaced the blocky CRT televisions in popularity.
- In several strips, Calvin bemoans the fact that he's missing some television show he wants to watch because he has to eat dinner or do his homework. Nowadays, you could just look up any show you want to watch on the Internet or watch it any time on a streaming service, so Calvin wouldn't have to "miss" anything.
- In one early 1986 strip, Calvin receives a Chain Letter in the mail. This dates the comic a bit, because by the 2000s chain emails or copypasta forum messages far exceeded physical chain mail letters in number because it was much easier and cheaper to send them to others over the Internet.
- In several strips Calvin is shown looking things up in the dictionary or the encyclopedia, as well as having to go to the library during the story arc where he's partnered up with Susie on a project about Mercury and the one where he had to do a report on bats, or when he wanted to learn more about snakes. Nowadays, he could much more easily look up anything he didn't know on the Internet (though, this being Calvin...).
- Invoked with one strip wherein Calvin's dad talked about wooden escalators. While they were very much outdated in The '90s- there were actually still a few that were in operation. At the time, King's Cross station in London and the Macy's at Herald Square in New York City had them.
- In a meta sense, Watterson often complained how newspapers were limiting the space and creativity of comic strips, how he was continuously fighting strict deadlines, and his constant arguments with the publishing syndicates over licensing rights and greater creative control, while at the same time repeatedly ridiculing the medium of comic books as being "incredibly stupid". Calvin and Hobbes ended shortly before Webcomics on the Internet were beginning to take off; webcomics are mostly self-published (so the author usually has total creative control), have virtually limitless creative space, no real schedule to keep, and have the potential to reach a large audience easily on the Internet (of course, the Internet is only mentioned in the strip once).
- Calvin puts his nose in a jar of mustard in one comic strip. You would be hard pressed to find mustard in anything but a plastic squeeze bottle after The '80s.
