When was the Samvatsari Parva observed for year 2021?

Samvatsari Parva is an important Jain festival that is celebrated during the last day of ‘Parva Paryushana’.
This year, it was observed on September 11.
During this festival, Jains fast and perform Pratikraman together. The poor are given alms and the picture of a Jina (great teacher) is carried through streets.