style - How can I make a non-linear timeline less confusing?

My story is broken into 8 sections. Sections 1 and 2 take place simultaneously, in two different worlds. The other 6 continue in a linear fashion (switching back & forth between the two worlds as needed).

Right now it's not particularly obvious that 1 and 2 are happening at the same time. There's only 1 character who appears in both (he appears towards the end of each section).

What can I do to make this more obvious to the reader?

Some options I've already considered:

• Give up and merge 1 and 2. I'm really trying to keep 1 and 2 separate - otherwise I'll be introducing about 20 different characters and worldbuilding info for 2 separate worlds all at once.


• Put dates on each chapter. This feels heavy-handed, and the two worlds aren't supposed to be using the same calendar.


• Leave it as is. Hopefully, the shared character gives enough information for the reader to figure it out. (The trick here is to make it look less forced.)

Edit: Time flows at the same rate in both worlds. Sections 1 & 2 last for 1 month.

There is one event at the beginning that affects both worlds, but it doesn't look the same in both worlds.

Answer

You have three issues to solve:

1. There are two different worlds.


2. The sequential nature of each world's chapters (that there are not gaps where the other world's chapters are).


3. The two timelines run simultaneously (vs one being a flashback or something).

I would solve 1 and 2 the same way: with a clear calendar system for each world that is different enough to show that they aren't different dates in the same system but totally different calendars.

For example:

• World 1: July 27, 3009.



• World 2: The 18th day of the 3rd month in the reign of Kala year 47.

Number 3 is a lot harder and the solution will need to revolve around the shared character. This isn't hard to do...it's hard to do well. Drop hints, show the character's thoughts if narration allows, or he can speak about the transition.

Do this subtly but more than once. It's easy for a reader to miss a single reference, but multiple references will get their attention. If the mission is the same or related, this may be the best way to make things clear.