wildfly/wildfly — pull request #6822 by emmartins (2014-10-14 19:57:20+00:00)
Title: WFLY-3766: fixing traditional cron behaviour in calendar based timeouts

Currently we leave our EJB expression based scheduling DST changes handling up to JDK Calendar, which is problematic in some use cases:
- when setting a time in DST rollback repeated period it will choose the later STD version, skipping the earlier DST version, this means period scheduling such as every 30 min will have skipped timeouts
- when setting a time in DST forward skipped period it will adjust time to original time + DST savings, which may skip timeouts between the beginning of DST period and such adjustment

This PR fixes the issues above implementing the traditional cron behaviour, i.e. on DST rollback "ambiguous" timeouts will be repeated, and on DST forward "non existent" timeouts will be skipped instead of adjusted.
Modern cron is not a must, will add later if requested.