Plugin development for contest

-- HikaShop version -- : 2.6.1
-- Joomla version -- : 3.5.0
-- PHP version -- : 5.3.24

I'm trying to develop a plugin that works off of the CRON task on the first of each month to go through entries in a table and pick a random winner from the previous month's entries. I'm not sure what's wrong with my code but something's not working. I've attached my plugin that I have so far. Any help would be appreciated. Thanks.

Hi,

Do you have tried all the if conditions ?
For example, instead of "date('n')" shouldn't it be "date('j')" ?

Then you have an error, you have to replace "$winner = pickWinner();" by "$winner = $this->pickWinner();"