In SQLite, date and time() functions are used to retrieve current date and time. The date and time functions use a subset of IS0-8601 date and time formats. 
There are 6 different date and time functions which return and do calculation on date and time in different formats:
| Index | 
Functions | 
Description | 
| 1) | 
SQLite date() function | 
The SQLite date() function is used to calculate the date and return it in the format 'YYYY-MM-DD'. | 
| 2) | 
SQLite datetime() function | 
 The SQLite datetime() function is used to calculate a date/time value, and return it in the format 'YYYY-MM-DD HH:MM:SS'. | 
| 3) | 
SQLite julianday() function | 
 The SQLite julianday() function returns the date according to julian day. A Julian Day is the number of days since Nov 24, 4714 BC 12:00pm Greenwich time in the Gregorian calendar.
It returns the date as a floating point number. | 
| 4) | 
SQLite now() function | 
Actually now is not a function. Rather than it is a timestring parameter which is used in various SQLite functions to retrieve the current date and time.  | 
| 5) | 
SQLite strftime() function | 
The SQLite strftime() function is used to return date in a formatted manner and also facilitates you to do calculation on dates.  | 
| 6) | 
SQLite time() function | 
 SQLite time() function is used to calculate time and return it in the format 'HH-MM-SS'.  |