You are, but this was a 6 year old blog post. The calendar has changed since then to mirror our own.
EDIT: With the exception of Leap Years, as written in the Inner Sea World Guide.
For simplicity's sake, I just use our calendar and change the names of the months.
I did search and find several references to the calendar of Golarion. The reference that I saw quoted several places was the one on the Paizo Blog. There was a reference to an entry in the Gazetteer which didn't talk about the # of days in each month. I found this entry on wikia which referred to the same Paizo Blog entry I had seen other places. I had seen the pathfinderwiki early on but didn't look at the sources at that time. When I continued to search I was unable to find any other references about the number of days in a month except what I saw on the Paizo Blog. I did look in the The Inner Sea World Guide Index and Glossary but didn't see anything about the Calendar of Golarion. I could probably go back and find about 2 dozen other posts and references that all contradicted each other. So with that I decided to post here just to be safe. Now that you have all pointed me to the correct reference I thank you.
Yup, the wikia wiki is old (hasn't been updated since 2010) the pathfinderwiki version of the wiki project has over 2 times as many pages and is actively kept as up to date as we can. Wikia is just dumb and doesn't take down old projects.