-
-
Date/Time Input
+
+
Date/Time Input
-General-use date and time is input using a wide range of
-styles, including ISO-compatible,
SQL-compatible,
-and other permutations of date and time. In cases where interpretation
-can be ambiguous (quite possible with many traditional styles of date
-specification)
Postgres uses a style setting
-to resolve the ambiguity.
-
+ General-use date and time is input using a wide range of
+
styles, including ISO-compatible,
SQL-compatible,
+ and other permutations of date and time. In cases where interpretation
+ can be ambiguous (quite possible with many traditional styles of date
+
specification)
Postgres uses a style setting
+ to resolve the ambiguity.
+
-Most date and time types share code for data input. For those types
-the input can have any of a wide variety of styles. For numeric date
-representations,
-European and US conventions can differ, and the proper interpretation
-is obtained by using the SET DATESTYLE
-command before entering data.
-Note that the style setting does not preclude use of various styles for input;
- it is used primarily to determine the output style and to resolve ambiguities.
-
+ Most date and time types share code for data input. For those types
+ the input can have any of a wide variety of styles. For numeric date
+ representations,
+ European and US conventions can differ, and the proper interpretation
+ is obtained by using the SET DATESTYLE
+ command before entering data.
+ Note that the style setting does not preclude use of various styles for input;
+ it is used primarily to determine the output style and to resolve ambiguities.
+
The special values current,
- The strings
- now,
- today,
- yesterday,
- tomorrow,
- and epoch
- can be used to specify
- time values. now
- means the current transaction time, and differs from
- current
- in that the current time is immediately substituted
- for it. epoch
- means Jan 1 00:00:00 1970 GMT.
-
+ The strings
+ now,
+ today,
+ yesterday,
+ tomorrow,
+ and epoch
+ can be used to specify time values.
+ now
+ means the current transaction time, and differs from
+ current
+ in that the current time is immediately substituted for it.
+ epoch means Jan 1 00:00:00 1970 GMT.
+
-
<productname>Postgres</productname> Date/Time Special Constants
-Constants
-
-
- |
- Constant
- Description
-
-
-
- |
- current
- Current transaction time, deferred
-
- |
- epoch
- 1970-01-01 00:00:00+00 (Unix system time zero)
-
- |
- infinity
- Later than other valid times
-
- |
- -infinity
- Earlier than other valid times
-
- |
- invalid
- Illegal entry
-
- |
- now
- Current transaction time
-
- |
- today
- Midnight today
-
- |
- tomorrow
- Midnight tomorrow
-
- |
- yesterday
- Midnight yesterday
-
-
-
-
-
+
<productname>Postgres</productname> Date/Time Special Constants
+ Constants
+
+
+ |
+ Constant
+ Description
+
+
+
+ |
+ current
+ Current transaction time, deferred
+
+ |
+ epoch
+ 1970-01-01 00:00:00+00 (Unix system time zero)
+
+ |
+ infinity
+ Later than other valid times
+
+ |
+ -infinity
+ Earlier than other valid times
+
+ |
+ invalid
+ Illegal entry
+
+ |
+ now
+ Current transaction time
+
+ |
+ today
+ Midnight today
+
+ |
+ tomorrow
+ Midnight tomorrow
+
+ |
+ yesterday
+ Midnight yesterday
+
+
+
+
+
+
+
<productname>Postgres</productname> Date Input
+ Date Inputs
+
+
+ |
+ Example
+ Description
+
+
+
+ |
+ January 8, 1999
+ Unambiguous text month
+
+ |
+ 1999-01-08
+ ISO-8601
+
+ |
+ 1/8/1999
+ US; read as August 1 in European mode
+
+ |
+ 8/1/1999
+ European; read as August 1 in US mode
+
+ |
+ 1/18/1999
+ US; read as January 18 in any mode
+
+ |
+ 1999.008
+ Year and day of year
+
+ |
+ 19990108
+ ISO-8601 year, month, day
+
+ |
+ 990108
+ ISO-8601 year, month, day
+
+ |
+ 1999.008
+ Year and day of year
+
+ |
+ 99008
+ Year and day of year
+
+ |
+ January 8, 99 BC
+ Year 99 before the Christian Era
+
+
+
+
+
+
+
<productname>Postgres</productname> Month Abbreviations
+ Month Abbreviations
+
+
+ |
+ Month
+ Abbreviations
+
+
+
+ |
+ April
+ Apr
+
+ |
+ August
+ Aug
+
+ |
+ December
+ Dec
+
+ |
+ February
+ Feb
+
+ |
+ January
+ Jan
+
+ |
+ July
+ Jul
+
+ |
+ June
+ Jun
+
+ |
+ March
+ Mar
+
+ |
+ November
+ Nov
+
+ |
+ October
+ Oct
+
+ |
+ September
+ Sep, Sept
+
+
+
+
+
+
+ The month May has no explicit abbreviation, for obvious reasons.
+
+
+
+
+
<productname>Postgres</productname> Day of Week Abbreviations
+ Day of Week Abbreviations
+
+
+ |
+ Day
+ Abbreviation
+
+
+
+ |
+ Sunday
+ Sun
+
+ |
+ Monday
+ Mon
+
+ |
+ Tuesday
+ Tue, Tues
+
+ |
+ Wednesday
+ Wed, Weds
+
+ |
+ Thursday
+ Thu, Thur, Thurs
+
+ |
+ Friday
+ Fri
+
+ |
+ Saturday
+ Sat
+
+
+
+
+
+
+
<productname>Postgres</productname> Time Input
+ Time Inputs
+
+
+ |
+ Example
+ Description
+
+
+
+ |
+ 04:05:06.789
+ ISO-8601, with all time fields
+
+ |
+ 04:05:06
+ ISO-8601
+
+ |
+ 04:05
+ ISO-8601
+
+ |
+ 040506
+ ISO-8601
+
+ |
+ 04:05 AM
+ Same as 04:05; AM does not affect value
+
+ |
+ 04:05 PM
+ Same as 16:05; input hour must be <= 12
+
+ |
+ z
+ Same as 00:00:00
+
+ |
+ zulu
+ Same as 00:00:00
+
+ |
+ allballs
+ Same as 00:00:00
+
+
+
+
+
+
+
<productname>Postgres</productname> Time Zone Input
+ Time Zone Inputs
+
+
+ |
+ Time Zone
+ Description
+
+
+
+ |
+ PST
+ Pacific Standard Time
+
+ |
+ -8:00
+ ISO-8601 offset for PST
+
+ |
+ -800
+ ISO-8601 offset for PST
+
+ |
+ -8
+ ISO-8601 offset for PST
+
+
+
+
+
+
+
<productname>Postgres</productname> Recognized Time Zones
+ Time Zones
+
+
+ |
+ Time Zone
+ Offset from UTC
+ Description
+
+
+
+ |
+ ACSST
+ +10:30
+ Central Australia Summer Std Time
+
+ |
+ ACST
+ +09:30
+ Central Australia Std Time
+
+ |
+ ADT
+ -02:00
+ Atlantic Daylight Time
+
+ |
+ AESST
+ +11:00
+ Australia Eastern Summer Std Time
+
+ |
+ AEST
+ +10:00
+ Australia Eastern Std Time
+
+ |
+ AHST
+ -10:00
+ Alaska-Hawaii Std Time
+
+ |
+ AST
+ -4:00
+ Atlantic Std Time (Canada)
+
+ |
+ AWSST
+ +9:00
+ Australia Western Summer Std Time
+
+ |
+ AWST
+ +8:00
+ Australia Western Std Time
+
+ |
+ BST
+ +1:00
+ British Summer Time
+
+ |
+ BT
+ +3:00
+ Baghdad Time
+
+ |
+ CADT
+ +10:30
+ Central Australia Daylight Savings Time
+
+ |
+ CAST
+ +09:30
+ Central Australia Std Time
+
+ |
+ CAT
+ -10:00
+ Central Alaska Time
+
+ |
+ CCT
+ +8:00
+ China Coastal Time
+
+ |
+ CDT
+ -5:00
+ Central Daylight Time
+
+ |
+ CET
+ +1:00
+ Central European Time
+
+ |
+ CETDST
+ +2:00
+ Central European Daylight Savings Time
+
+ |
+ CST
+ +6:00
+ Central Std Time
+
+ |
+ DNT
+ +1:00
+ Dansk Normal Tid
+
+ |
+ DST
+ +1:00
+ Dansk Standard Time (?)
+
+ |
+ EAST
+ +10:00
+ East Australian Std Time
+
+ |
+ EDT
+ -4:00
+ Eastern Daylight Time
+
+ |
+ EET
+ +2:00
+ Eastern Europe, USSR Zone 1
+
+ |
+ EETDST
+ +3:00
+ Eastern Europe Daylight Savings Time
+
+ |
+ EST
+ -5:00
+ Eastern Standard Time
+
+ |
+ FST
+ +1:00
+ French Summer Time
+
+ |
+ FWT
+ +2:00
+ French Winter Time
+
+ |
+ GMT
+ 0:00
+ Greenwish Mean Time
+
+ |
+ GST
+ +10:00
+ Guam Std Time, USSR Zone 9
+
+ |
+ HDT
+ -9:00
+ Hawaii/Alaska
+
+ |
+ IDLE
+ +12:00
+ International Date Line, East
+
+ |
+ IDLW
+ -12:00
+ International Date Line, West
+
+ |
+ IST
+ +2:00
+ Israel
+
+ |
+ IT
+ +3:40
+ Iran Time
+
+ |
+ JST
+ +9:00
+ Japan Std Time,USSR Zone 8
+
+ |
+ JT
+ +7:30
+ Java Time
+
+ |
+ KST
+ +9:00
+ Korea Standard Time
+
+ |
+ LIGT
+ +10:00
+ Melbourne, Australia
+
+ |
+ MDT
+ -6:00
+ Mountain Daylight Time
+
+ |
+ MEST
+ +2:00
+ Middle Europe Summer Time
+
+ |
+ MET
+ +1:00
+ Middle Europe Time
+
+ |
+ METDST
+ +2:00
+ Middle Europe Daylight Time
+
+ |
+ MEWT
+ +1:00
+ Middle Europe Winter Time
+
+ |
+ MEZ
+ +1:00
+ Middle Europe Zone
+
+ |
+ MST
+ -7:00
+ Mountain Standard Time
+
+ |
+ MT
+ +8:30
+ Moluccas Time
+
+ |
+ NDT
+ -2:30
+ Newfoundland Daylight Time
+
+ |
+ NFT
+ -3:30
+ Newfoundland Standard Time
+
+ |
+ NOR
+ +1:00
+ Norway Standard Time
+
+ |
+ NST
+ -3:30
+ Newfoundland Standard Time
+
+ |
+ NT
+ -11:00
+ Nome Time
+
+ |
+ NZDT
+ +13:00
+ New Zealand Daylight Time
+
+ |
+ NZST
+ +12:00
+ New Zealand Std Time
+
+ |
+ NZT
+ +12:00
+ New Zealand Time
+
+ |
+ PDT
+ -7:00
+ Pacific Daylight Time
+
+ |
+ PST
+ -8:00
+ Pacific Std Time
+
+ |
+ SADT
+ +10:30
+ South Australian Daylight Time
+
+ |
+ SAT
+ +9:30
+ South Australian Std Time
+
+ |
+ SET
+ +1:00
+ Seychelles Time
+
+ |
+ SST
+ +2:00
+ Swedish Summer Time
+
+ |
+ SWT
+ +1:00
+ Swedish Winter Time
+
+ |
+ WADT
+ +8:00
+ West Australian Daylight Time
+
+ |
+ WAST
+ +7:00
+ West Australian Std Time
+
+ |
+ WAT
+ -1:00
+ West Africa Time
+
+ |
+ WDT
+ +9:00
+ West Australian Daylight Time
+
+ |
+ WET
+ 0:00
+ Western Europe
+
+ |
+ WETDST
+ +1:00
+ Western Europe Daylight Savings Time
+
+ |
+ WST
+ +8:00
+ West Australian Std Time
+
+ |
+ YDT
+ -8:00
+ Yukon Daylight Time
+
+ |
+ YST
+ -9:00
+ Yukon Standard Time
+
+ |
+ ZP4
+ -4:00
+ GMT +4 hours
+
+ |
+ ZP5
+ -5:00
+ GMT +5 hours
+
+ |
+ ZP6
+ -6:00
+ GMT +6 hours
+
+
+
+
+
+ If the compiler option USE_AUSTRALIAN_RULES is set
+ then EST refers to Australia Eastern Std Time,
+ which has an offset of +10:00 hours from UTC.
+
+
+ It is interesting that Australian time zones and their naming variants
+ account for fully one quarter of all time zones in the
+
Postgres time zone lookup table.
+
+
+
+
Date/Time Input Interpretation
+
+ Break the input string into tokens and categorize each token as
+ a string, time, time zone, or number.
+
+
+
+
+ If the token contains a colon (":"), this is a time string.
+
+
+
+
+ If the token contains a dash ("-"), slash ("/"), or dot ("."),
+ this is a date string which may have a text month.
+
+
+
+
+ If the token is numeric only, then it is either a single field
+ or an ISO-8601 concatenated date (e.g. "19990113" for January 13, 1999)
+ or time (e.g. 141516 for 14:15:16).
+
+
+
+ If the token starts with a plus ("+") or minus ("-"),
+ then it is either a time zone or a special field.
+
+
+
+
+
+
+ If the token is a text string, match up with possible strings.
+
+
+
+
+ Do a binary-search table lookup for the token
+ as either a special string (e.g. today),
+ day (e.g. Thursday),
+ month (e.g. January), or noise word (e.g. on).
+
+ Set field values and bit mask for fields.
+ For example, set year, month, day for today, and additionally
+ hour, minute, second for now.
+
+
+
+
+ If not found, do a similar binary-search table lookup to match
+ the token with a time zone.
+
+
+
+
+ If not found, throw an error.
+
+
+
+
+
+
+ The token is a number or number field. If there are more than 4 digits,
+ and if no other date fields have been previously read, then interpret
+ as a "concatenated date".
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
projects / postgresql.git / commitdiff