Bet probability

#1
In a given year starting from January 1st through the end of the year, let's say there are 26 babies being born. If I made a bet that none of those 26 babies would be born in December, the chances of me winning my bet would be 11/12 to the 26th power correct? (Assuming every month consists of 30 days.

Now what if I wanted to make a bet that from those 26 baby births, there would be one month in which none of the babies were born. I know my chances of winning this bet increases, because I am not only limited to the month of December, it can be any month. For example, if none of the babies are born in February I win, if none of the babies are born in March I would also win, etc. How do I go about making this calculation?