Originally Posted by
Anonymoose
For this kind of speculation, it's important to note that this difference is inherently relative.
Within each individual shard, time is passing at the same pace. However, due to the chaotic nature of the Rift, time is apparently "at different places" between shards relative to each other. This also oscillates. One shard might be "faster" than another at one point, and "slower" than that same shard later on. This was the case with the Source and the First, with them just "passing one another" and "catching up to each other' at this present moment. (How convenient for the plot!)