Board Thread:Questions and Answers/@comment-7736895-20140705234342/@comment-11571396-20140706040926

There is no separate timelines for the main and side stories, they are all classified under the Unified Story Timeline. The reason for this is that, aside from SS1, you can read the side stories in any order you want without it hindering your reading experience, but let me try to help you:

1. SS1 is a side story following directly Volume 13, which is a rather strange case as it doesn't read like one and could easily have been a correct volume.

2. SS2 is a collection of the recountings of loosely interconnected events around a same theme, all taking place on Fridays. As it takes place throughout the current year, you can read it whenever you want, but preferrably after Volume 16, for no other reason that it came out after it in order of publication and is placed as such on Bakatsuki. Actually, read before New Testament, an important character and his plot related power will be extremely relevant later on.

3. Styil SS, Mars SS, Mark Space SS, and Uiharu SS are all joined under the volume ToAru SP. The 3 first stories are not specified when they take place, but Uiharu SS takes place on August 1st, but it has no incidence on the main story so you can pretty much read it whenever you want (it is however advised that you read Styil SS and Mark Space SS before New Testament as characters introduced in them appears in the main story and takes major roles in New Testament).

4. Norse Mythology SS or Kanzaki SS is to read absolutely before starying New Testament. Concepts and characters important in the second part of the series are crucial to be understood before then. No specific date for the events as well, it is presumed that they take place throughout the current year.

5. Railgun SS: Shopping Mall Demonstration. Takes place on July 1st, mostly unconsequential as the event takes place before the main story technically starts (July 19), but it is suggested to read it before Volume 17, in which characters in the SS are introduced to the main story.

6. Railgun SS: Liberal Arts City. Takes place on September 3rd. To read before Volume 15, one character comes back in that volume.

7. Road to Endymion SS: Takes place between September 10 and 12, and between Volumes 7 and 8, however was released years later, as such, reading after them is not a problem. Has no incidence on the story, only connected to the movie (so read it before watching the movie), which was itself retconned into the timeline.

8. Necessarius SS is the most recent side story, and focus on the Amakusa, as such only read it after finishing Volume 7.

In short, there is no need for a separate timeline, dated events are already compiled, non dated can't be.