give a meaningful error if it is empty and disallow it instead of having
an implicit default (the default should be set by the component using
the calendarevent, not the calendarevent itself)
also add regression tests
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
else an event like "61" never finishes when calculating the next event
also add regression tests for this and other range checks
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
otherwise the numbers are sorted like this:
[1,10,11 .. 19, 2, 20, ..]
which would lead to the wrong next time
also add regression tests for this and mixed forms like:
20..22:*/30
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
