How to calculate the difference between two timestamps using the TIMEDIFF() function?

TIMEDIFF(from_time, to_time) is a MySQL built-in function that calculates the difference from one timestamp to another. For example:

SELECT TIMEDIFF('2028-12-31 23:59:59', '2028-12-30 01:01:01.000002');
  -- +---------------------------------------------------------------+
  -- | TIMEDIFF('2028-12-31 23:59:59', '2028-12-30 01:01:01.000002') |
  -- +---------------------------------------------------------------+
  -- | 46:58:57.999998                                               |
  -- +---------------------------------------------------------------+

SELECT TIMEDIFF('2028-12-31 23:59:59', '2029-01-01 01:01:01.000002');
  -- +---------------------------------------------------------------+
  -- | TIMEDIFF('2028-12-31 23:59:59', '2029-01-01 01:01:01.000002') |
  -- +---------------------------------------------------------------+
  -- | -01:01:02.000002                                              |
  -- +---------------------------------------------------------------+

SELECT TIMEDIFF('2028-12-31 23:59:59', '2029-01-01 01:01:01.000002')-1;
  -- +-----------------------------------------------------------------+
  -- | TIMEDIFF('2028-12-31 23:59:59', '2029-01-01 01:01:01.000002')-1 |
  -- +-----------------------------------------------------------------+
  -- |                                                   -10103.000002 |
  -- +-----------------------------------------------------------------+

SELECT TIMEDIFF('23:59:59', '01:01:01.000002');
  -- +-----------------------------------------+
  -- | TIMEDIFF('23:59:59', '01:01:01.000002') |
  -- +-----------------------------------------+
  -- | 22:58:57.999998                         |
  -- +-----------------------------------------+

Reference information of the TIMEDIFF() function:

TIMEDIFF(from_time, to_time): time
  Subtracts to_time from from_time and returns the difference
  as a time value.

Arguments, return value and availability:
  from_time: Required. The timestamp to be subtracted from.
  to_time: Required. The timestamp to be subtracted.
  time: Return value. The difference as a time value.
  Available since MySQL 4.

Related MySQL functions:

• TIMESTAMP() - Adding Time to Timestamp

⇒ TIMESTAMP() - Adding Time to Timestamp

⇐ TIME() - Extracting Time

⇑ MySQL Functions on Date and Time

⇑⇑ MySQL Function References