title: Enum of days in Java with Calendar
body: <p>I would like to know if there is an existing enum containing all the week days in Java. I'm using Calendar to treat time logic but I didn't see anything like this (I could create it myself but I 'd rather use something existing). I also saw the <a href="http://threeten.sourceforge.net/" rel="noreferrer">threeten project</a> but it's still in alpha. Since an enum containing days of week is so trivial it's shown by sun in the enum documentation, I was thinking something may already exist. Any ideas ?</p>