This document discusses date and time functions in SQL. It defines the datetime datatypes as DATE, TIMESTAMP, TIMESTAMP WITH TIME ZONE, and TIMESTAMP WITH LOCAL TIME ZONE, and the interval datatypes as INTERVAL YEAR TO MONTH and INTERVAL DAY TO SECOND. It also lists the date parts YEAR, MONTH, DAY, HOUR, MINUTE, SECOND, and provides examples of date/time formats and a basic SQL SELECT statement to retrieve orders on a specific date.