but my problem is TIMING.
The forum gets this question every so often... For example:
http://forum.arduino.cc/index.php?topic=121088.0
Essentially, while the Arduino has a reasonably accurate resonator, it is not as accurate as a precision quartz/watch crystal. For under $20, you can add a very accurate time base:
For constant year in, year out accuracy there are solutions that include GPS or Internet Time Servers.
My clock:
http://www.hackster.io/rayburne/5-billion-arduino-gps-clock-for-25
Ray