A cron expression has six mandatory fields (or slots) and one optional field. Adjacent fields are separated by a space. The asterisk
* is a wild card meaning "any legal values". In theory, we could construct an empty expression that would look like this:
* * * * * * *. (This expression will not work in OpenCms for reasons explained below.)
The source of information for this text is the JavaDoc (documentation contained in the source code) for the
CmsScheduledJobInfo class. For more information, you can consult thesource code.
Each field in a cron expression stands for a particular time period. Here is a list of the fields with all of their legal values: