This is a set of Scala wrappers and DSL around the Quartz scheduling library.
If you've had trouble remembering which column in the cron expression corresponds to what, this DSL is for you. Using it, you can just say Cron(hours=12) to schedule an event at 12 o'clock every day- the default for the unspecified time units is the * wildcard.
You can also use ranges like Cron(month=3 to 6) or a set of values like Cron(minutes=Set(15,20,30)). You can even use a step like Cron(dayOfMonth=1 by 5) meaning every 5th day starting with the 1st.
For week days and months you can use three-letter abbreviations so that you can tell easily which one you're talking about- isn't Cron(dayOfWeek=Mon to Fri) or Cron(month=Set(Mar,Apr,May)) more readable?
Finally, if you try to construct a cron sub-expression which not among the values allowed for the specified time unit, you will get an IllegalArgumentException.