For anyone who encountered an issue where the extension would fail to load because of a DbQueryError on a Sqlite installation. I managed to track down the issue in the MsCalendar.sql syntax. Here is a Sqlite compatible version.
CREATE TABLE IF NOT EXISTS mscal_names(
ID INTEGER PRIMARY KEY,
Cal_Name varchar(255) NOT NULL
);
CREATE TABLE IF NOT EXISTS mscal_list (
ID INTEGER PRIMARY KEY,
`Date` DATE NOT NULL,
Text_ID INTEGER NOT NULL,
Day_of_Set INTEGER NOT NULL DEFAULT 1,
Cal_ID INTEGER NOT NULL
);
CREATE TABLE IF NOT EXISTS mscal_content (
ID INTEGER PRIMARY KEY,
Text varchar(255) NOT NULL,
Start_Date DATE NOT NULL,
Duration INTEGER NOT NULL,
Yearly INTEGER NOT NULL
);