concerning rtc's, and the crystals. is it correct to say (im trying to understand) that clocks lose time because of the crystal accuracy? and if so, is the crystal accuracy affected by temperature? if this is a true statement, then if my clock crystal was kept at a constant temperature in theory, my clock should keep time pretty well, right? are all rtc's created equal? perhaps accuracy is not the correct word for this maybe tolerance? im not sure. are some crystals (manufacturers) better than others? my ds1305 has lost quite a bit of time over the last 2 months, but it resides in a room that has 15 degree minimum temperature swings daily. is the 1305 just a piece of cr@p? or is it the crystal. any help in understanding this from an rtc person greatly appreciated. thank you.