How to Modify Greeting Card Sound PCB for Repeating Alarm with Battery Saving?

I'm interested in making a toy with the sound PCB and components from a greeting card. When the card is open, I would like to control the off time and have it repeat continually. I want to use it as an alarm but make the batteries last.

You could use a 555 timer to turn the card on and off or to act in place of the switch that activates the card when it's opened. Use a CMOS 555 for low drain and so you can use large resistors, so the capacitor won't have to be as large. You can use a tantalum cap, to get large capacitance in small size.

Or, you could use a CMOS 4060 which is an osc and 14 stage ripple counter that is perfectly suited to generating long time delays.