There is no timing in between branches. Some branches are dependent on other branches but most stand for themselves. That is the main reason why the story seems quite chaotic and unconnected (ie wife loses her anal virginity 4 times iirc: husband, Mark, Greg and a black guy). Even if some timing is 'designed', the ability to pause branches and resume them at will, multiple actions which take time (evening) available at the same moment, not reading messages when they first appear or simply spamming wait->wait->wait->next_day will destroy any non enforced timing.
While these independencies make the game chaotic as long as multiple branches are kept active, it does make the development easier. If alle branches would depent on all others, the whole game would either end up as a single branch or each branch, even each step of every branch, would be a highly complex construct having to take into account every possible actions taken before.
