Chronos

Chronos is a simple mod to control the length of a Minecraft day.

It has no configuration file, and a single command: /timescale.

To set the day length to twice the normal length:

/timescale set 0.5

To set the day length of half the normal length:

/timescale set 2

To view the current time scale for the world you are in:

/timescale

Time scale is stored per dimension in a file called Chronos.dat.