For businesses in Manitoba collecting Provincial Sales Tax (PST) .. Effective February 1, 2008:
..When the return due date falles on a weekend or a public holiday, the due date is the next business day.
This relates to PST collections starting January 2008, which is due by the 20th of the following month – which is Wednesday February 20, 2008.
The December 2007 PST collections, however .. due on January 20, 2008 – which falls on a Sunday – is still due this Friday January 18, 2008.