Appendix B. Date/Time Support
PostgreSQL uses an internal heuristic
parser for all date/time input support. Dates and times are input as
strings, and are broken up into distinct fields with a preliminary
determination of what kind of information may be in the
field. Each field is interpreted and either assigned a numeric
value, ignored, or rejected.
The parser contains internal lookup tables for all textual fields,
including months, days of the week, and time zones.
This appendix includes information on the content of these
lookup tables and describes the steps used by the parser to decode
dates and times.