I was recently surprised to find that EXTRACT's day of the week

numbering is different than TO_CHAR's ditto. EXTRACT starts at 0==Sunday
while TO_CHAR starts at 1==Sunday.

A suggestion for two documentation notes is attached as a patch to
current CVS HEAD.

Troels Arvin

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 15774a3a00ad171ddac6c3df246eda977e3f3b15..2de07c04ae83a82692de33c56b392d035dec088b 100644 (file)
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,5 +1,5 @@
 
 
@@ -4412,6 +4412,13 @@ substring('foobar' from 'o(.)b')   o
        1230 microseconds = 2.021230 seconds. 
       
      
+
+     
+      to_char's day of the week numbering
+        (see the 'D' formatting pattern) is different from that of the 
+        extract function.
+      
+     
     
    
 
@@ -5146,6 +5153,11 @@ SELECT EXTRACT(DECADE FROM TIMESTAMP '2001-02-16 20:38:40');
 SELECT EXTRACT(DOW FROM TIMESTAMP '2001-02-16 20:38:40');
 Result: 5
 
+       
+        Note that extract's day of the week numbering is 
+        different from that of the to_char function.
+       
+