#TIME ZONES ISO#

If no time zone is stated in the input string, then it is assumed to be in the time zone indicated by the system's TimeZone parameter, and is converted to UTC using the offset for the timezone zone. An input value that has an explicit time zone specified is converted to UTC using the appropriate offset for that time zone. That is, the resulting value is derived from the date/time fields in the input value, and is not adjusted for time zone.įor timestamp with time zone, the internally stored value is always in UTC (Universal Coordinated Time, traditionally known as Greenwich Mean Time, GMT). In a literal that has been determined to be timestamp without time zone, PostgreSQL will silently ignore any time zone indication. To ensure that a literal is treated as timestamp with time zone, give it the correct explicit type: PostgreSQL never examines the content of a literal string before determining its type, and therefore will treat both of the above as timestamp without time zone. The SQL standard differentiates timestamp without time zone and timestamp with time zone literals by the presence of a “ +” or “ -” symbol and time zone offset after the time.

#TIME ZONES ISO#

(Alternatively, AD/ BC can appear before the time zone, but this is not the preferred ordering.) Thus:Īre valid values, which follow the ISO 8601 standard. Valid input for the time stamp types consists of the concatenation of a date and a time, followed by an optional time zone, followed by an optional AD or BC. If no precision is specified in a constant specification, it defaults to the precision of the literal value (but not more than 6 digits). Precision can be specified for time, timestamp, and interval types, and can range from 0 to 6. Where p is an optional precision specification giving the number of fractional digits in the seconds field. SQL requires the following syntax type ' value' Refer to Section 4.1.2.7 for more information. Remember that any date or time literal input needs to be enclosed in single quotes, like text strings. See Appendix B for the exact parsing rules of date/time input and for the recognized text fields including months, days of the week, and time zones. PostgreSQL is more flexible in handling date/time input than the SQL standard requires. Set the DateStyle parameter to MDY to select month-day-year interpretation, DMY to select day-month-year interpretation, or YMD to select year-month-day interpretation. For some formats, ordering of day, month, and year in date input is ambiguous and there is support for specifying the expected ordering of these fields. In most cases, a combination of date, time, timestamp without time zone, and timestamp with time zone should provide a complete range of date/time functionality required by any application.ĭate and time input is accepted in almost any reasonable format, including ISO 8601, SQL-compatible, traditional POSTGRES, and others.

The type time with time zone is defined by the SQL standard, but the definition exhibits properties which lead to questionable usefulness. Note that if both fields and p are specified, the fields must include SECOND, since the precision applies only to the seconds. The interval type has an additional option, which is to restrict the set of stored fields by writing one of these phrases: By default, there is no explicit bound on precision. Time, timestamp, and interval accept an optional precision value p which specifies the number of fractional digits retained in the seconds field. timestamptz is accepted as an abbreviation for timestamp with time zone this is a PostgreSQL extension. The SQL standard requires that writing just timestamp be equivalent to timestamp without time zone, and PostgreSQL honors that behavior.

Time zones