As part as a hobby project I built a relatively simple BCD binary LED clock using a PIC micro controller and a DS1307 RTC. Upon battery power loss the DS1307 resets back to 01/01/00 00:00:00 which makes sense. However, since the user is only able to see hours, minutes and seconds on my clock it makes no sense to set the date.
My question is, what is the relevance of setting the date in a DS1307 in relation to timekeeping. As far as i know the only relationship between time and date is a leap second correction every few years which i doubt the DS1307 implements.
Is it okay to let the date remain 01/01/00? I would assume it wouldn't make the time drift a lot but maybe i am missing something.
Either way, it's just a hobby clock, accuracy isn't mission critical, I'm merely asking out of curiosity.
Thanks in advance!
Best Answer
You may very well operate the RTC chip by leaving the "date" field at its initial default value. You will find however, as you enable the RTC to count the "time" field that once each 24 hours the "date" field will accumulate another day.
Setting the "date" field or not will not be having any impact on the RTC's accuracy or in its power consumption in any realistically measurable way.
I have not worked with any RTC's with an "daylight savings time feature" (DST) but if there was an RTC with such feature and it was enabled you would see that interact with your "time" field. In that case you would probably want to have your time piece comprehend the date. Like I said though it is unlikely to find an RTC chip with DST feature as such feature is different in many parts of the world and is subject to change in any particular area at the whim of governmental types.