-- -- HOROLOGY -- -- -- datetime, timespan arithmetic -- SELECT datetime '1996-03-01' - timespan '1 second' AS "Feb 29"; SELECT datetime '1999-03-01' - timespan '1 second' AS "Feb 28"; SELECT datetime '2000-03-01' - timespan '1 second' AS "Feb 29"; SELECT datetime '1999-12-01' + timespan '1 month - 1 second' AS "Dec 31"; CREATE TABLE TEMP_DATETIME (f1 datetime); -- get some candidate input values INSERT INTO TEMP_DATETIME (f1) SELECT d1 FROM DATETIME_TBL WHERE d1 BETWEEN '13-jun-1957' AND '1-jan-1997' OR d1 BETWEEN '1-jan-1999' AND '1-jan-2010'; SELECT '' AS ten, f1 AS datetime FROM TEMP_DATETIME ORDER BY datetime; SELECT '' AS hundred, d.f1 AS datetime, t.f1 AS timespan, d.f1 + t.f1 AS plus FROM TEMP_DATETIME d, TIMESPAN_TBL t ORDER BY plus, datetime, timespan; SELECT '' AS hundred, d.f1 AS datetime, t.f1 AS timespan, d.f1 - t.f1 AS minus FROM TEMP_DATETIME d, TIMESPAN_TBL t WHERE isfinite(d.f1) ORDER BY minus, datetime, timespan; SELECT '' AS ten, d.f1 AS datetime, datetime '1980-01-06 00:00 GMT' AS gpstime_zero, d.f1 - datetime '1980-01-06 00:00 GMT' AS difference FROM TEMP_DATETIME d ORDER BY difference; SELECT '' AS hundred, d1.f1 AS datetime1, d2.f1 AS datetime2, d1.f1 - d2.f1 AS difference FROM TEMP_DATETIME d1, TEMP_DATETIME d2 ORDER BY datetime1, datetime2, difference; SELECT '' as fifty, d1 as datetime, date_part('year', d1) AS year, date_part('month', d1) AS month, date_part('day',d1) AS day, date_part('hour', d1) AS hour, date_part('minute', d1) AS minute, date_part('second', d1) AS second FROM DATETIME_TBL WHERE isfinite(d1) and d1 >= '1-jan-1900 GMT' ORDER BY datetime; -- -- abstime, reltime arithmetic -- SELECT '' AS four, f1 AS abstime, date_part('year', f1) AS year, date_part('month', f1) AS month, date_part('day',f1) AS day, date_part('hour', f1) AS hour, date_part('minute', f1) AS minute, date_part('second', f1) AS second FROM ABSTIME_TBL WHERE isfinite(f1) and f1 <> abstime 'current' ORDER BY abstime; -- -- conversions -- SELECT '' AS ten, f1 AS datetime, date( f1) AS date FROM TEMP_DATETIME WHERE f1 <> datetime 'current' ORDER BY date; SELECT '' AS ten, f1 AS datetime, abstime( f1) AS abstime FROM TEMP_DATETIME ORDER BY abstime; SELECT '' AS five, f1 AS abstime, date( f1) AS date FROM ABSTIME_TBL WHERE isfinite(f1) AND f1 <> abstime 'current' ORDER BY date; SELECT '' AS five, d1 AS datetime, abstime(d1) AS abstime FROM DATETIME_TBL WHERE NOT isfinite(d1); SELECT '' AS three, f1 as abstime, datetime(f1) AS datetime FROM ABSTIME_TBL WHERE NOT isfinite(f1); SELECT '' AS ten, f1 AS timespan, reltime( f1) AS reltime FROM TIMESPAN_TBL; SELECT '' AS six, f1 as reltime, timespan( f1) AS timespan FROM RELTIME_TBL; DROP TABLE TEMP_DATETIME; -- -- formats -- SET DateStyle TO 'US,Postgres'; SHOW DateStyle; SELECT '' AS sixty_two, d1 AS us_postgres FROM DATETIME_TBL; SELECT '' AS eight, f1 AS us_postgres FROM ABSTIME_TBL; SET DateStyle TO 'US,ISO'; SELECT '' AS sixty_two, d1 AS us_iso FROM DATETIME_TBL; SELECT '' AS eight, f1 AS us_iso FROM ABSTIME_TBL; SET DateStyle TO 'US,SQL'; SHOW DateStyle; SELECT '' AS sixty_two, d1 AS us_sql FROM DATETIME_TBL; SELECT '' AS eight, f1 AS us_sql FROM ABSTIME_TBL; SET DateStyle TO 'European,Postgres'; SHOW DateStyle; INSERT INTO DATETIME_TBL VALUES('13/06/1957'); SELECT count(*) as one FROM DATETIME_TBL WHERE d1 = 'Jun 13 1957'; SELECT '' AS sixty_three, d1 AS european_postgres FROM DATETIME_TBL; SELECT '' AS eight, f1 AS european_postgres FROM ABSTIME_TBL; SET DateStyle TO 'European,ISO'; SHOW DateStyle; SELECT '' AS sixty_three, d1 AS european_iso FROM DATETIME_TBL; SELECT '' AS eight, f1 AS european_iso FROM ABSTIME_TBL; SET DateStyle TO 'European,SQL'; SHOW DateStyle; SELECT '' AS sixty_three, d1 AS european_sql FROM DATETIME_TBL; SELECT '' AS eight, f1 AS european_sql FROM ABSTIME_TBL; RESET DateStyle; SHOW DateStyle; -- -- formats -- SET DateStyle TO 'US,Postgres'; SHOW DateStyle; SELECT '' AS sixty_two, d1 AS us_postgres FROM DATETIME_TBL; SELECT '' AS eight, f1 AS us_postgres FROM ABSTIME_TBL; SET DateStyle TO 'US,ISO'; SELECT '' AS sixty_two, d1 AS us_iso FROM DATETIME_TBL; SELECT '' AS eight, f1 AS us_iso FROM ABSTIME_TBL; SET DateStyle TO 'US,SQL'; SHOW DateStyle; SELECT '' AS sixty_two, d1 AS us_sql FROM DATETIME_TBL; SELECT '' AS eight, f1 AS us_sql FROM ABSTIME_TBL; SET DateStyle TO 'European,Postgres'; SHOW DateStyle; INSERT INTO DATETIME_TBL VALUES('13/06/1957'); SELECT count(*) as one FROM DATETIME_TBL WHERE d1 = 'Jun 13 1957'; SELECT '' AS sixty_three, d1 AS european_postgres FROM DATETIME_TBL; SELECT '' AS eight, f1 AS european_postgres FROM ABSTIME_TBL; SET DateStyle TO 'European,ISO'; SHOW DateStyle; SELECT '' AS sixty_three, d1 AS european_iso FROM DATETIME_TBL; SELECT '' AS eight, f1 AS european_iso FROM ABSTIME_TBL; SET DateStyle TO 'European,SQL'; SHOW DateStyle; SELECT '' AS sixty_three, d1 AS european_sql FROM DATETIME_TBL; SELECT '' AS eight, f1 AS european_sql FROM ABSTIME_TBL; RESET DateStyle; SHOW DateStyle;