Anglophone canonical sources are rather vague up until Beast Wars.
Japanese sources offer more insight.
2007
- The events of KISS Players happens.
- The events of Music Label happens.
2010
- The events of G1 cartoon Season 3 happens. Although this happened in 2005 in Anglophone canon, in Japan it happened in 2010 (hence why the Japanese dub of S3 is called "Transformers 2010")
2011
- The events of "The Headmasters" happens, including the destruction of Cybertron. But Cybertron is restored by the end of the decade because reasons.
2020
- The events of "Super God Masterforce" happens. Eh!
2021
- The events of Unite Warriors happens.
2022
- The events of Legends Vol. 57 and Vol. EX (Greatshot) begins.
2023
- The events of Legends Revival Vol. 1 happens.
2025
- The events of "Transformers Victory" happens.
- The events of the 'Hero Set' (Classic Pretenders sans shells) happens.
- The events of Legends Revival Vol. 2 happens.
2026
- The events of Legends Vol. EX (Greatshot) concludes.
- The events of "Transformers Zone" (including extended canon) happens between 2026 and 2030.
2031
- The events of "Battlestars" happens.
2035
- The events of "Operation Combination" (and extended canon) happens.
2036
- The Prime Mode Plague happens.
Late 2030s
- The events of Transformers: Generation 2 (and extended canon) happens (note that in Anglophone canon, G2 happens in 1993-95)
2039
- A ceasefire is declared between the Autobots and Decepticons.
2040
- The Great War between the Autobots and Decepticons ends.
- Humans create the android beings Artemis and Moon.
24th Century
- The events of Beast Wars begins here.
- The events of Beast Machines happens.
Tens of thousands of years later
- The events of Beast Wars Second happens.
A few years after that
- The events of Beast Wars Neo happens.