In the free version of the calendar, unfortunately, you can not add events in February, because the script automatically assigns it to March. Similarly, when you click on the link "Fri, Feb 1" refers to the March calendar. In what may be a problem?
This could be because of a known bug in free version that can't handle the day light savings time correctly. This problem does not appear in the premium version. I can put in a ticket to address this issue in the free version.