Been thinking about the timing of VSMP a lot, and as much as it's always gonna be a little vague, you can get pretty far with pinning it down. You do have to exclude some anachronisms (Beyonce and Twilight, for example) which makes it more subjective as the series COULD be taking place in 2005 if you really stretch it, but I'm going to assume it's somewhere around the 1800s based on the general vibes of everyone involved.
There are a few things mentioned that give us a lower bound on how far technology has progressed. Trains (first invented 1804, made public 1830) are a big one - Shelby and Drift talk about wanting Scott to ride one - but those two also say in the finale that they live in small apartments / flats, which were also introduced for the public in the 1830s. Soon after this in the finale, when Abolish gets turned, he says it felt like having an IV in. Technically IVs in some form have existed since the 1600s, but the safe version of it we use today was invented in 1852. Abolish's organization should theoretically have easier or earlier access to IVs than most people, but he says it like he thinks the other townsfolk would know what it is, so I'm going to say 1852 is a good technological bound for when Vampires could take place.
Next we get the war timing, mostly thanks to Legundo's backstory and Owen's depictions of it, such as this image of one of his memories:
It does look very much like world war one. I wouldn't be surprised if that was the inspiration, but similar wars happened on smaller scales a lot earlier than the 1910s. The first major trench war was in Crimea (1853-1856), and the first machine guns were invented around 1860, though the first self-powered one (I assume that's what were seeing in the image) - the Maxim gun - was invented in 1884, and spread quickly all across Europe. The Crimean war also notably involved mass civilian casualties during its sieges, which could be where a lot of Legundo's kill count comes from, as well as large scale shelling like what we see in the image (and hear, in the video). Lastly, we have to note that Legundo refers to the time he's been a doctor as "decades". So if his final conflict was Crimea or around that time, the series would be in the 1870s-1880s, but if we take the machine gun to be realistic it would be more in the 1900s-1910s. (He could also have been a soldier for decades as well, depending on his age.)
I'm going off of memory for this one, but I think in the first episode there's an interaction where Drift mentions movie theaters and Cleo asks "What's a movie?", presumably because she doesn't know much about what humans have been doing for the past 70 years (OOC I think they just weren't sure if the timing matches up, but I'm going to say it does because why not). The first publicly screened film was released in 1895 but they weren't really movies in the way we know them until around 1910. Combined with the machine gun timing, this gives us the nice opportunity to say the series is in 1906 and that there's a hundred-year time gap before the epilogue - or in 1897 to line up with Dracula if you want. I've seen people say you could push it further to the interwar period (1930s if Legs fought in WWI), but I'm pretty sure no one mentions cars at all. If it's past 1908, when the Model T was developed, I feel like they'd come up alongside trains as a point of conversation at least once, so 1906 seems like the best choice to fit everything in.
