Quote Originally Posted by richard View Post
it might be easier to use a PCF8563 rtc chip with built in alarm and interrupt output
I use one of these on my wireless remote rain guage its a good thing. works at 3v too

i'd need to see the full code to see whats wrong with your project
I have a DS1307 RTC chip, but for some reason in the original project this gave me a lot of issues as the time would randomly revert to 10:10:10 and thus screw up the timings. I'll have a look at the 8563 chip, but really wanted to steer away from external chips in case the same issue happens again