Add load caps in minimal arduino circuit?

I am trying to build a nice sleeping arduino, using schematics from here (http://interface.khm.de/index.php/lab/experiments/sleep_watchdog_battery/)
I need to know if I have to include load caps for the 16mhz crystal. I am using interrupts mostly, but I will aadd delay functionality. It will have to be off for possibly 4 hours at a time- maybe up to 24 hours if I go really slow- exact timing is not a problem, I just need it to be power efficient. About how much drift would I have using a watchdog timer for a 24 hour delay? Would it just be easier to have an RTC?

iceng5 years ago
No need for caps except C1.
I don't think you understand the watchdog, you wont get 4 hrs let alone
24 hrs out of it.
Depends on the RTC if you mean less power or easy to do.

A
astroboy907 (author)  iceng5 years ago
Ok- thanks. Guess I dont understand watchdog yet- anyways re thought the long timer and decided it wasnt needed...
I have a DS1307 RTC