Oracle Julian day of year
If you check the TO_CHAR (datetime) documentation you get a link to "Format Models" with a comprehensive list of available formats. I guess you want this:
DDDDay of year (1-366)
One way would be to use:
select sysdate - trunc(sysdate,'yyyy') from dual'Trunc' cuts everything except the year and returns 01/01/2014, subtracted by the sysdate returns numbers of days since 1st of january.