Many family trusts have December year-ends. A trust must file a T3 return within 90 days of their year-end. So, in this non-leap year the deadline is March 31, which is coming up soon.
Due to the introduction of the punitive tax on split income rules (TOSI), there are likely fewer trusts being used to pay dividends to family members this year. You still have to file the trust return and it is best to file it on time.