直接从DOCS

sqlite does not have a storage class set aside for storing dates and/or times. Instead,the built-in Date And Time Functions of sqlite are capable of storing dates and times as TEXT,REAL,or INTEGER values:

• TEXT as ISO8601 strings (“YYYY-MM-DD HH:MM:SS.SSS”).
• REAL as Julian day numbers,the number of days since noon in Greenwich on November 24,4714 B.C. according to the proleptic Gregorian calendar.
• INTEGER as Unix Time,the number of seconds since 1970-01-01 00:00:00 UTC.

Applications can chose to store dates and times in any of these formats and freely convert between formats using the built-in date and time functions.

sqlite内置的日期和时间功能可以是found here。