You have 60 days from the date WCAT made its decision to file for judicial review. This 60-day time limit runs from the date the decision was made even if you received the decision sometime after it was made.
If you do not file within the time limit, you may lose your right to apply for judicial review. It is possible to apply for an extension of time but there is no guarantee that the judge will give you one.
The best plan is to apply for judicial review well before your deadline just in case something goes wrong or you have not counted the days properly.