Consider becoming a Patron.

This mod changes the lengths of the days (simple mode) or makes them mimic a certain timezone and a lat-long coordinate (realistic mode).

How to edit the timedilation.toml

Simple Mode

Simple mode changes how fast the game ticks daytime ticks (not game ticks).
The TOML snippet for a simple time dilator for a dimension called `modid:dimension` is as follows:

["modid:dimension"]

speed = 2.0 # twice as fast as a normal minecraft day
type = "simple"

Note: even if the speed is a whole number *remember to include the decimal part (.0)*

Realistic Mode

Realistic mode makes the sunset and sunrise sync somewhat with a real location and timezone.
Realistic mode requires a timezone (tz database name in the list at https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) and a location in lat-long coordinates. Note that south and west values are negative, while north and east values are positive.

["modid:dimension"]

timezone = "Europe/Copenhagen" # the timezone

type = "realistic" # using a timezone and coordinates

["modid:dimension".location]

latitude = 55.6761 # south is negative

longitude = 12.5683 # west is negative

Credits

Mike Reedell - sunrisesunsetlib (https://github.com/mikereedell/sunrisesunsetlib-java)

Time Dilation