How were the dates for the timeline determined?
A lot of very careful research, intense discussion and ultimately pure guesswork. Unfortunately George has not been very helpful in this regard and does not include any dates in the narrative of the books (except one). Most of the dates in the timeline are based on several Key Dates, these are mostly birthdays, from which we can extrapolate estimates for birth, conception and even a character’s death. As we build up a framework of these dates other events can be positioned in relation to them based on a character’s age at the time of certain events and the juxtaposition to other related events. We can also factor in distance and travel time required between locations based on the distances on the map and our knowledge of real world travel limitations. However this is all purely based on guesswork. There is only one fixed date in the entire series that we can be 100% sure of and that is the events of 1 January 300 since it is specifically mentioned in the text that this day is the start
