Except it isn't a hundred, it's sixty, and I protest that usage. >.<. I prefer eighteen o'clock.
Just imagine all the idioms they have to account for in these voice algorithms. I know in German they also handle "halb neun" correctly as 8:30.
Although it does have a problem with hours over 20 (“22 o’clock” becomes 20:02 for some reason, possibly because of my thick Italian accent).