Use variable setting, not hard coded default

[appelflap]

Could not create a pull request with only this change, because I also changed the Time library. But here is the change: ee1553d

[mikalhart]

Thank you @appelflap. Good catch.

Hey, I saw your port to Arduino Time.h (from *nix time). Can you explain what benefit that gave you?

M

[appelflap]

Only reason is that I couldn't find the time.h (lowercase 't') for the Arduino IDE. And it wasn't included in my IDE by default. I am using an Arduino pro mini from Sparkfun.