DuckTales is a timeless series, having aged considerably well for an animated television show from the '80s. The high quality of the stories and character certainly help, but a big part of the Disney series' staying power is that it was never topical. The original DuckTales told stories about ancient legends and treasure without commenting on whatever time period Scrooge and his nephews were living in, and the new show looks to be doing the same. When does the DuckTales revival take place? It's easier to define the time period by when it doesn't take place.
The DuckTales reboot doesn't stick to a set time period, but indicates its relative timeline through the technology that's used. In any of the promos for the new show, you'd be hard-pressed to find Scrooge scrolling through a smart phone or Huey, Dewey, and Louie plugging into a VR headset. While 2017 submarines are surely state-of-the-art affairs, a preview clip from the new DuckTales shows a submarine with technology that looks more appropriate for the '50s or '60s. Later in the preview, when Huey decides to play some sea shanties, he pulls out a portable radio instead of an iPod or a bluetooth speaker. It's not clear when exactly DuckTales takes place, but it's clearly not in the present day.
The DuckTales revival follows in the footsteps of the original, not spending time trying to comment on the world around it. Instead, the new show creates its own world that can be stretched and molded to fit whatever adventure that Scrooge and his nephews are going on. While the ducks of DuckTales don't use smartphones or fidget spinners, they do get to be friends with the technologically advanced hero Gizmoduck. The ducks, especially the adventurous Webby, even have access to technology like night-vision goggles and grappling hooks. While I can at least guess that they are in the 20th century, DuckTales seems to be open to incorporating technology as the show sees fit.
Going off of the portable radio in Huey's possession and Gizmoduck's Robocop look, it seems that the DuckTales revival could be taking place in a time period as late as the '80s, placing it in the same time period as the original show. It may not stick to just technology that would have been found in that decade, but by not trying to capture 2017 gadgets on screen, the show ensures that it will age far better than a version of DuckTales where everyone has a smartwatch.
But the lack of modern technology isn't the only thing that makes DuckTales feel like a throwback. The show doesn't subscribe to current trends in fashion or music, indicating that this update is meant to be far more than just "DuckTales in 2017." The reboot is a new story told with familiar characters, set in its own version of reality.
Ultimately, DuckTales has always been about adventure, friendship, and family — themes that fit easily into any time period, even one that's completely fictional.