Designed for a Space:1889v1 setting with historical divergence after 1866.
Organization is by Day and Month if known. Items dated to just a year follow the more exact monthly listing.
IRL used in comments is "In Real Life'.
Known additions from Frank Chadwick's original Space:1889v1 timeline have a blue text and will will only interleave in the real date section if a specific date was given.
RBT game specific additions will be in purple text. Some IRL events are commented if game changes may make them obsolete.
Updates include Wikipedia Space:1889 article and additional historical data reference from web sources.
credit: Based on Maateen Greenway's original timeline.