大比丘三千威儀 2.57

2.57

揵椎有五事：一者常會時、二者旦食時、三者晝飯時、四者暮投槃時、五者一切無常。

Striking the ghaṇṭā has five occasions: 1. The regular assembly. 2. The morning meal. 3. The midday meal. 4. Evening basin-returning (putting away utensils). 5. Any impermanence (death).