Initially, timecyc.dat only has 8 different clock configurations. This plugin fixes this, now the game will read 24 different parameters for each hour, as was the case in all GTA games.
Installation: move the .asi file and the Data folder to the game folder. There is no need to delete the original timecyc.dat!
The archive also contains a Python script for converting the time cycle to timecyc_24h.