The bots can answer questions about the current date and time from the "WatchStateMachine", which is a default Self script under the Program page. You can also write your own script that uses date/time in Self, or AIML.
Your bot's scripts seem ok, and it can answer "what is the date", so something odd is going on. Looking into it, some how your bot learned that "date ?" was a compound word (like "chat bot"), so it was answering the question "what is 'date ?'". I fixed it by deleting the "date ?" compound word from the Knowledge page, so it seems ok now.
I will look into it further, let me know if it happens again.