I've been re-watching "Batman: The Animated Series" (still as awesome as ever!) and I'm confused on what time period it's set in. The cars, buildings, and clothing imply that it's mid-twentieth century but Batman has advanced technology in the bat cave which makes me think that it's more modern. Is there an official answer?
Batman the Animated Series (September 5, 1992) was inspired by a variety of previous animated series including the famed Max Fleischer's, Superman produced by Fleischer Studios in the 1940s and based on the artwork of producer and artist Bruce Timm. Timm was also inspired by the various Batman series, both animated and live action. You can see his homages in his depictions of the Batmobile, the Batcave and the technology used by Batman.
A homage to the live-action Batmobile launching sequence, complete with the flame jet and fins.
Considering its influences, it was designed to have a relatively timeless appearance with the automobiles having a rounded 1940-1950s look but having more modern looking trains. There are dirigibles and helicopters, so it mixes and matches technology from a range of modern eras ranging from the 40s to the 90s.
The look even coined its own name, "Dark Deco" which was a mix of retro-modern appearance and intentionally obfuscates what era it is meant to depict. This look was perpetuated in the later Superman the Animated Series and the Justice League Animated Series spin-offs. The look is designed to represent a relatively modern time period without giving too many hints of the era of its origin literally creating a cartoon outside of time.
Take a look at the Max Fleischer Superman and you will be amazed at how forward-thinking those images appear today.
Actually they state on the DVD's that the series is heavily influenced by artwork from the 1930's up until the 1950's, and there are a massive amount of references to that time period (References to television shows, certain terminology, the fact that they still have typewriters). Overall I like to think it's set in the fifties, and the dialogue is intentionally written to reflect the common lingua franca of the era. Though it should be noted that when the series was re-vamped to match up with Superman, it changed drastically to be more modern (Which killed it for me). Things like black and white televisions (Which only appeared after the first few episodes by the way) became colour, and the people started wearing insanely tiny skirts and tee-shirts instead of ties and nice suits.
Best episodes ever: "The Jokers Favor" and "Harleys Holiday"
I need to agree with most of you all, and I feel too that it takes place during the 1940's-50's. However, I need to point out that in the volume 1 episode "Heart of Ice", Alfred asks Bruce if he's playing video games! So back then, video games never existed, if it were set in the 1940's-50's. Its interesting to analyze, and I think possibly the comic books (haven't read them), the time-line those were made back then, set the style for the Batman universe overall. I'm sure too that the original Batman timeline was set in the 1940's-50's but I may be wrong, and because the series was made in the 90's, it can't help but somehow have little present day (1990's) references.
From what I read, it takes place in the '90s and has modern technology. But the imagery is very 1940s/1950s era. And it was deliberate from the creators because they wanted the "Dark Deco", Film Noir look to this series (it was based off of older Batman versions). I agree with another commenter that this portrayal was lost when the series moved to TNBA, where everything looked more streamlined and modern; it was less stylized than BTAS.
The beginning of the series is in the late 40's - early 50's. By the time TNBA and Superman came out it was the Late 50's - 60's. That explains why the characters have shorter skirts and wear t-shirts and jeans. In our reality, the 1960's became more casual with younger people. Thats why Dick Grayson looks like a greaser and Tim Drake is wearing chuck taylors and t-shirts. By the time Justice League happens, it becomes more modern still by going into the 80's/90's but looking like the early 2000's. Which can explain why Batman Beyond is uber futuristic with flying cars and wacky clothes. Its basically blade runner but in Batman.