Opera Omnia launched in Japan almost one year before its Global release. Over time, the GL version has been catching up here and there, but we are still around 8 months behind the JP version. This may have its downsides – they get new events and cool toys to play with way ahead of us – but it also blesses us with the gift of foresight, allowing us to predict roughly when new characters, weapons or events will come.
Listed below are some great sources for that information.
Websites (mobile-friendly):
Tonberry Troupe’s Global Timeline
Including links to the featured characters’ infographics!
https://www.tonberrytroupe.com/timeline
FFOOtip: web app forecast and character helper
Also suggests the recommended artifacts and summon board passives for each character!
https://ffootip.com/
Image timelines
(Source) Posted by JakeMattAntonio on Reddit.