Real time fiction dates back to the climactic structure of classical Greek drama.
[1] Often, use of split screens or picture-in-pictures are used to show events occurring at the same time, or the context in which various subplots are affecting each other.
In comic books, the use of real time is made more complicated by the fact that most serial comics are released on a monthly basis and are traditionally 20 to 30 pages long, making it difficult to tell a story set in real time without overlooking important events from one month to the next.
Another explanation is the prevalence of the superhero genre in American comics, and the iconic status attached to such characters; it is often considered that such mythological, sometimes godlike heroes cannot age in real time without losing the characteristics that make them special.
In the Inspector Rebus series of detective novels by Scottish writer Ian Rankin, characters age in step with the publication date.