555 timer: how to set values to take an hour
As awesome as the 555 is, its drift may be a bit too high for periods this long. 

I recommend you look at using a MCU instead, such as the ATtiny4. It comes in SOT23-6 packaging and has an internal RC oscillator which is reasonably accurate. 

If you move up to a ATtiny25/45/85 (SOIC-8/DIL-8/QFN-20) then you can program it using the Arduino IDE once you have installed arduino-tiny, plus it can support an external 32.768kHz watch crystal which will improve accuracy by several orders of magnitude.