D&D 5E The Mutliverse and Time

[MG.0]

But looking at the 1E Manual of the Planes, perceived time varies by plane explicitly - See pages 6 and 7.

Sure, but that is something different entirely. In fact it explicitly says "Time is a constant in the known planes of existence, and cannot be expanded, contracted, created, or destroyed. The length of a day in one plane is the same number as the length of a day in another plane." When it speaks about varying time on different planes it is speaking of subjective time, which is the rate at which time affects living things. What it calls true time never varies. Calendar days would be a measure of true time, not subjective time. A DM certainly can rule otherwise or create planes which don't follow known laws, of course. In fact, I never cared for the subjective time thing. It complicates bookeeping on the inner planes for no real benefit other than a bit of local color. The Astral and Ethereal subjective times were likely adjusted because adventurers were meant to spend time travelling here and could become lost without the ability to find any natively occuring food. Personally I think they shouldv'e packed more food.

 

[Lucas Yew]

Time is relative.

No, seriously.

 

[MG.0]

Here's another fan created timeline using material from a bunch of sources, including Planescape, Ravenloft, and Spelljammer. There are contradictions among the sources so you have to choose the "correct" one for you.

 

[Majoru Oakheart]

Hmm, not sure which book that would be, unless it was from a 2nd edition book at the very end of the 90's, in which case I may have missed it. Unless you're counting something from Dragon magazine or the like, I can 't imagine where in 1st edition something like that would be hiding.

I know that the 2e Realmspace book talked about the sanctum that Elminster has on another planet in Realmspace where he has a permanent portal to the "real world" in the 1880s, I believe. He apparently makes trips there and has made a friend who regularly gives him "German Beer" which he finds delicious.

 

[Sword of Spirit]

There are a variety of official points where the time of X event on World A = the time of Y event on World B. Most of that is from the 2e era. Because we are dealing with lots of people creating this material (novels are one of the main sources) there are discrepancies, but it is still possible to create a fairly consistent multiverse timeline by selecting which sources you lend more weight to (ie, Spelljammer products take precedence, or the Forgotten Realms is the gold standard for time, etc).

The two main timelines I looked at were the Spelljammer one linked to above and another one that focuses on the Forgotten Realms, while still including other settings, called A Temporal Chronology of the Primes. The original site is down, but the Wayback Machine is your friend.

I like the Spelljammer one better, but I eventually decided to just go with my own points of correspondence. Decide what date in each world I want to be Date X, and say those all correlate as the same date. (And these chronologies are close enough that the variances between chronologies are not huge. For instance, the "current events" represented by products set in the Forgotten Realms, Greyhawk, and Dragonlance books were all assumed to be taking place within a couple decades of each other.)

You will not find anyone attempting to take into account varying lengths of years and such. That is a fool's undertaking. Instead, you can come up with something close enough for most fantasy needs by doing something like this: Number each day of the year. Start at the winter solstice or whenever, and go from 1 to 364/365. For calendars of different lengths, spread out or condense those days.

You now know that 13__ Dale Reckoning is the same as 5__ Greyhawk time. You are in the Realms on day 34 of the year. If you go to Oerth, it is whatever day of their year is labeled "34". If you visit a world with a shorter calendar like Krynn, maybe there isn't a day 34. Maybe it jumps from 33 to 35. Flip a coin as to which day you arrive at. If you go to a long calendar world like Athas, maybe there are two days that are both "Day 34". Flip that coin. The point is that your solstices and equinoxes line up and your years are magically the same length. I recommend having day and night synchronized on all worlds. It is magic, so it's okay if the multiverse keeps things aligned in mystically relativistic ways.

So yes, others have made good attempts at it, and it is rather fun to play with.