I have some irregular jobs to do(frequent and many), so I can't use the crontab.

for example:

* send an email at 10:20AM on July 22 2012
* post a article at 11PM tonight
* run a script at 9:50AM tomorrow.

I found the linux commond `at`, but that can't be managed easily, otherwise, I search some message queue (like zeromq) and gearman, they can't do scheduled jobs or delayed jobs too.

Are there other solutions?