how to set a wakealarm in F20

[dcw]

I would like to set a wakealarm so that my computer will boot up at a 
certain time.
In researching this, all I have found includes altering the 
/etc/rc.d/init.d/halt, which is present if F19 but not in F20.
I have not been able to find anything in systemd about doing this.

Has any one been able to do this. Any pointers in where to look for 
information.

Thanks, David