The Malayalam Calendar, or the Kollam Era (Malayalam: കൊല്ലവർഷം, romanized: Kollavaṟṣaṁ), is a sidereal solar calendar used in Kerala. The origin of the calendar has been dated to 825 CE, commemorating the establishment of Kollam.
There are many theories regarding the origin of the era, but according to recent scholarship, it commemorated the foundation of Kollam by Maruwan Sapir Iso, who was the leader of Persian Christian Settlers and trading guilds like Anjuvannam following the liberation of the Kingdom of Venad from the Chola rule by or with the assistance of the Chera emperor at Kodungallur. The Quilon Syrian copper plates were grants and privileges given to the trading guilds involved in the establishment of Kollam by Sthanu Ravi Varma.