Week numbers in Oracle
How to get the week number from a date
To get the ISO week number (1-53) from a date in the column datecol, use SELECT TO_CHAR(datecol, 'IW') FROM …
.
To get the corresponding four-digit year, use SELECT TO_CHAR(datecol, 'IYYY') FROM …
.
Read more about TO_CHAR() in the Oracle manual.
Read more
Learn more about week numbers and the ISO week numbering scheme in this little primer.