adafruit/RTClib — pull request #24 by mic159 (2014-02-20 13:41:41+00:00)
Title: Using PROGMEM to reduce RAM usage

This modification will allow you to easily store the
__DATE__ and __TIME__ strings in PROGMEM to stop them
from wasting SRAM.
It uses the __FlashStringHelper, which is the same as
what Serial.print() uses and is provided by default in
Arduino.