I'm currently experimenting with 1.8.8, forge version 11.15.0.1625.
The clock info line displays weird values, an example is a day taking longer than 24 hours.
https://dl.dropboxusercontent.com/u/13531495/ShareX/2015/12/2015-12-13_15-50-32.png
https://dl.dropboxusercontent.com/u/13531495/ShareX/2015/12/2015-12-13_15-54-31.png
Goes up to 29:59, then resets to 06:00.

Looks like from 1.8 to 1.8.8 the time values have shifted in the Minecraft code. Trying to determine what the new values are.

This is a bug with 1.8.8 Forge. I submitted a bug report on the Forge forums.

http://www.minecraftforge.net/forum/index.php/topic,35453.0.html

Ah, very interesting.
That also explains the other time-related problems I didn't mention here.

LexManos fixed it and said it would be in the next Forge build.