The first two parts of World of Krypton are pretty easy to place in order. In my mind, they are the start of Superman's history. Then, the story jumps by millennia to a point much closer to modern history. In this gap fits The Kents (currently incompletely reviewed by myself), again a no-brainer. Following this comes Starman #51, where Jor-El's attention is focused to Earth. After this comes the second half of World of Kryrpton, taking place at any point between the start of the 20th century and the start of World War 2. Now, that dating is a little arbitrary, and it assumes two things:
- Superman/Clark Kent is approximately 30 years old at the conclusion of the Man of Steel miniseries, and ages very, very slowly from there on. This would place his arrival on Earth in the 1950s (although with the normal sliding scale of comic-book dating, it's currently mid-1970s, but at the time of Man of Steel the 1950s date would have been appropriate).
- The journey of the birthing matrix from Krypton to Earth is not an instant or short one. I surmise that it is not travelling faster than light, and is in fact travelling very slowly. As revealed during the Exile storyline, Kryptonians were gentically bound to their homeworld, and would die if they left Krypton. With this in mind, it is unlikely that Kryptonian scientists would have spent any time developing space travel. There have been occasions where Superman has travelled the distance between Earth and Krypton in a short space of time, and indeed, during the final battle with Superboy-Prime in Infinite Crisis #7, Krypton seems to be very close to Earth. Because Kal-El was not born in the traditional sense, and the craft in which he travelled to Earth was specifically called a birthing matrix, the journey to from Krypton could quite happily have taken years without affecting his age at all.
For instance, the climax of Man of Steel #1 is the reveal of Superman for the first time. Therefore, this issue occurs in this chronology after the early exploits of Clark Kent, despite the issue featuring the destruction of Krypton, and the moment where as a teenager Clark discovers part of his heritage.
Another example is World of Krypton #4. Despite having a present-day framing sequence concurrent with teh main comics published that month, the key moment in this issue is the destruction of Krypton, hence its early appearance in the timeline.
An exception to this rule is the World of Smallville miniseries. Although the flashbacks include revelations about the relationship of Ma and Pa Kent, the framing sequences and contents of issues #3 and #4 follow and expand upon revelations made in the Millennium crossover. For me, it makes more sense to tackle this series in the wake of Millennium event, rather than insert them based on their flashbacks into their historical postion.
Next time on World of Superman: As promised, the Secret Origin of Perry White.