select (timestamp '2005-01-17 10:00' - timestamp '2005-01-01'); 

16 10:10

select (timestamp '2005-01-17 10:00' - timestamp '2005-01-01') / 7; 

2 08:17:08.571429

select (timestamp '2005-01-17 10:00' - timestamp '2005-01-01') day; 

16

select cast((timestamp '2005-01-17 10:00' - timestamp '2005-01-01') day as integer) / 7;

2

select floor((timestamp '2005-01-17 10:00' - timestamp '2005-01-01') / interval '7');

2

select timestamptz '2009-05-29 15:21:00.456789';

2009-05-2915:21:00.456789-04

select timestamptz '2009-05-28';

2009-05-2800:00:00-04

select timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2009-05-28';

1 15:21:00.456789

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2009-05-28');

1 15:21:00.456789

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2009-05-28')(3);

1 15:21:00.457

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2009-05-28')second;

141660.456789

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2009-05-28') year;

0

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2007-01-01') month;

28

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2007-01-01') year;

2

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2007-01-01') year to month;

2-4

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2009-05-28') second(3);

141660.457

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2009-05-28') minute(3);

2361

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2009-05-28') minute;

2361

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2009-05-28') minute to second(3);

2361:00.457

select (timestamptz '2009-05-29 15:21:00.456789'-timestamptz '2009-05-28') minute to second;

2361:00.456789