Board Thread:Bug Reports/@comment-82.230.230.17-20160622055707/@comment-27219153-20160622225952

There is a different command for changing the time in middle earth. It is /lotr_time set day

If the daylight cycle is still not happening, try /gamerule doDaylightCycle true

Also, in middle earth it takes 40 minutes to complete the day/night cycle as opposed to the usual 20 minutes in the overworld.