Thanks for your help. I was able to find the file and change the setting.
How I can override this file instead of hacking the file?
I tried to place the file here:
/templates/rt_acronym/html/com_jevents/views/alternative/helpers/alternativebuildmonthselect.php
but it is not working - drop-down shows the same amount of month. But when I hack the file, it changes the month number.
Please advise,
Sandra