Currently we have things listed with the GAME CANON dates not the dates which are canon to CHAPsverse. Just trying to figure stuff out in the mean time
Year 987 BCE
Kalos War (possibly against Galar or Paldea?)
Year 1868 CE(? sometimes mid-1800s)
The events of Pokemon Legends: Arceus
Year 1996 CE
The events of RGBY/FRLG
Leaf, Blue and Red (all aged 10) leave Palette Town on their Pokémon journeys. During this time frame, Team Rocket attempts to take over the Kanto region but is stopped by this trio. Eventually, Blue becomes Champion but quickly gets dethroned by Red.
Ages
Leaf, Blue, and Red begin their journeys at 10 years old.
Year 1997 CE
The events of Emerald (mixed with ORAS)
Brendan, the son of Professor Birch, enlists the help of Norman's daughter May in doing research for his father. Team Magma & Aqua attempt to awaken slumbering legendary pokemon to bring their dreams into reality but are thwarted
Ages
Brendan & May are 12; Wally is 10
Leaf, Blue and Red are 11-ish
Between 1997 and 1998
The events of Pokemon Colosseum and Pokemon Ranger occurs
Leaf meets Mewtwo
Blue becomes Gym Leader of Viridian City
Year 1999 CE
The events of GSC/HGSSS, Pokemon Rangers Shadows over Almia & Pokemon Rangers Guardian Signs occur
Ethan, Kris and Lyra begin their pokemon journey, only for Silver to steal one of Elm's pokemon. Team Rocket, revived, cause the Lake of Rage incident. All four of them are 10 years old
Ages
Ethan, Kris, Lyra, are around 10 years old, at most 14.
Silver is around 9 to 15
Leaf, Blue, Red, Brendan and May are 13-14 years old (depending on birthdays)
May and Brendan are 14 to 15, Wally is 12
Year 2000 CE
The events of DPPt/DBSP
Lucas, Dawn and Barry begin their pokemon journey, assisting Prof Rowan. The eventually assist in taking down Team Galactic
Lucas, Dawn and Berry are around 10 years old, at most 14.
Cynthia is older than the protagonists but how older is unknown
Leaf, Blue, Red = 14 to 15
Brandon, May = 15 to 16
Ethan/Kris/Lyra = 11 to 15
Between 2002 and 2003
The events of Pokemon Colosseum XD: Gale of Darkness (5 years after PC)
Year 2010 CE
The events of BW
Hilbert, Hilda, Cheren, and Bianca start their pokemon journey in Unova. They take down Team Plasma, N disappears with a legendary dragon and Hilbert(?) goes looking for him
Ages
Hilbert, Hilda, Cheren, and Bianca are 14
N is 20
Leaf, Blue, Red = 24 to 25
Brandon, May = 25 to 26
Ethan/Kris/Lyra = 21 to 25
Lucas/Dawn/Berry = 20 to 24
Between 2011 and 2012
Between the events of BW and B2W2, Bianca becomes Prof Juniper's assistant, Cheren, Roxie and Marlon becomes gym leaders, Iris becomes the new champion, the Pokemon World Tournament is formed (and Hilda gets traumatized by Cynthia)
Year 2012 CE
The events of B2W2 & XY
Rosa and Nate receive a pokemon. Hugh's sister's Purlloin is stolen from Team Plasma. New adventures in Unova region. N and Hilbert return,
Ages
Rose, Nate, and Hugh are likely 12;
Leaf, Blue, Red = 24 to 25
Brandon, May = 25 to 26
Ethan/Kris/Lyra = 21 to 25
Lucas/Dawn/Berry = 20 to 24
Hilbert, Hilda, Cheren, and Bianca are 16
N is 22
Year 2013
The events of XY
Calem and Serena meet Shauna, Tierno and Trevor and do wowrk for Professor Sycamore. Team Flare attempts to use the ultimate weapon to elimiate all life in the world but is thwarted
Ages
Calen / Serena are likely 12
Leaf, Blue, Red = 25 to 26
Brandon, May = 26 to 27
Ethan/Kris/Lyra = 22 to 26
Lucas/Dawn/Berry = 21 to 25
Hilbert, Hilda, Cheren, and Bianca are 17
N is 23
Rose, Nate, and Hugh are likely 13;
Year 2016 CE
The events of Ultra Sun☼plugin-autotooltip__default plugin-autotooltip_bigyear decided based on Porygon's Pokedex entry
20 years should have passed between RGBY/FRLG
Selene and Elio, after living in Alola for 3 months, journeys across the islandsm encountering Team Skull, the Aether Foundation and Ultra Wormholes
Ages
???
Red, Blue and Leaf should all be around 30, and pretty set in their respective marriages/relationships