Just an update...
With the latest dev build as of 12FEB, we now have;
CronFiveMinutes (runs every 5 minutes)
CronFifteenMinutes (runs every 15 minutes)
CronThirtyMinutes (run every 30 minutes, like 06:00 and 06:30 of each hour)
as an addition to the already running ones as;
CronHourly (runs every hour)
CronNightly (runs every day at 01:00 UTC)
CronWeekly (runs every week, when a new week starts at Sunday 00:00 UTC)
CronMonthly (runs every first day of the month at 00:00 UTC)