How long would it take me to catch up?

Hey. So I stopped watching Pokemon a little bit after diamond and pearl started, just cuz I kinda grew out of it. However with the release of Pokemon go, I reminisced on my memories of Pokemon as a child, and wondered if the show was still even going. I quickly found out that there have been 2 whole new generations since diamond pearl ended.

My question is, how long would it take for me to catch up if I pick up where I left off in DP? Would it take way too long? Would it be more sensible to just skip what I missed and go straight to XY? What are your guys' opinions on this? Thanks!

I would watch the DP episodes. It one one of the better seasons.

BW is good. I liked it, but a lot of people didn't because it was a soft reboot which potentially reset Ash's skill level to a new trainer and age. However, the story got a lot better. At least in the Team Rocket and Team Plasma Arcs. I would at least watch those.

XY and XYZ are by far the best seasons of pokemon ever. Being the first seasons that I couldn't wait for the next episode. The start of XY after the first gym gets extremely slow, but then picks up after the 2nd gym. But I would highly suggest watching XY and XYZ to the fullest.

I don't know exactly where you stopped in DP, but counting it, you have a total of about 445 episodes to catch up to where the Japanese Version currently is. About 10 to 15 more for English Dub.

Each episode is about 20 minutes, you have about 149 hours total to watch. Basically half the episodes that are currently out.

Highlights I would say to watch are these:
Dawn's Contest Episodes. (DP Saga)
Hunter J Episodes (DP Saga)
Team Galactic Episodes (DP Saga)
Tournament Episodes (BW Saga)
Team Rocket Arc (BW Saga)
Team Plasma Arc (BW Saga)
Ash's Badge and Rival Episodes (All Sagas)
League Episodes (All Sagas)
Catching Pokemon Episodes (All Sagas)
XY and XYZ (All Episodes)

Most fillers in XY and XYZ are really good. And I don't mind watching them.

Edit: Sinnoh Episodes are full of fillers as it lasted for about 5 years in the US. Unova has a lot of fillers as well. I would list every episode I think you should watch, but that would be really hard to do when even I don't know which episodes are which.

Don't leave DP and dont watch BW if u watch BW u will hate anime :D