use a PC connected to a relay card, the connection can be either thru RS232 port, or parallel port of more relays are needed.
The advantage here is that....
1. Any PC from the school's computer department can be used for this task (though access to it must be restricted).
2. PC based software are easy to design. You can have more than 40-50 events in this case. The interface is easy design using VB or Delphi. The events can all be linked to a database that is very easy to manage. Perhaps a web-interface can also be used if required. All these can be designed and made by a VB/Delphi programmer.
3. The relay card is a simple affair, just one or two relays connected via opto-isolators to the RTS and DTR pins of the RS 232 port. Since only the relay needs to be switched ON/OFF no PIC or micro-controller is needed, thus eliminating programmer/firmware programming task.
4. No need to bother about date/time management as PCs have very reliable and accurate RTC.
The PC can be switched ON in the morning before the school opens. The application can be run in the startup.
If you are designing this for someone then try to convince him/her about the advantages of using a PC based system instead of a standalone one.
But if you are making this for a school project then I guess you can't the original project specs.
thanks
n