PostgreSQL

If the numeric token contains a colon (:), this is a time string. Include all subsequent digits and colons.

If the numeric token contains a dash (-), slash (/), or two or more dots (.), this is a date string which might have a text month. If a date token has already been seen, it is instead interpreted as a time zone name (e.g., America/New_York).

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 numeric time zone or a special field.

See if the token matches any known time zone abbreviation. These abbreviations are supplied by the configuration file described in Section B.4.

If not found, search an internal table to match the token as either a special string (e.g., today), day (e.g., Thursday), month (e.g., January), or noise word (e.g., at, on).

If still not found, throw an error.

If there are eight or six digits, and if no other date fields have been previously read, then interpret as a “[.quote]#concatenated date”# (e.g., 19990118 or 990118). The interpretation is YYYYMMDD or YYMMDD.

If the token is three digits and a year has already been read, then interpret as day of year.

If four or six digits and a year has already been read, then interpret as a time (HHMM or HHMMSS).

If three or more digits and no date fields have yet been found, interpret as a year (this forces yy-mm-dd ordering of the remaining date fields).

Otherwise the date field ordering is assumed to follow the DateStyle setting: mm-dd-yy, dd-mm-yy, or yy-mm-dd. Throw an error if a month or day field is found to be out of range.