Ben Primrose <bprimr...@tracelink.com> writes: > Iâm seeing some odd behavior from the extract function. > Any idea why extract would think January 3rd of next year is the 53rd week > of the year?
See the fine manual ... http://www.postgresql.org/docs/9.3/static/functions-datetime.html#FUNCTIONS-DATETIME-EXTRACT week The number of the ISO 8601 week-numbering week of the year. By definition, ISO weeks start on Mondays and the first week of a year contains January 4 of that year. In other words, the first Thursday of a year is in week 1 of that year. In the ISO week-numbering system, it is possible for early-January dates to be part of the 52nd or 53rd week of the previous year, and for late-December dates to be part of the first week of the next year. For example, 2005-01-01 is part of the 53rd week of year 2004, and 2006-01-01 is part of the 52nd week of year 2005, while 2012-12-31 is part of the first week of 2013. It's recommended to use the isoyear field together with week to get consistent results. Depending on what you want to define a "week" as, you can probably get what you want from some other EXTRACT() property. "doy" div 7 might help, for example. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
