Hi Jorge,

Do you have more than one of these units made? If so is the same problem happening to each of them or only the one unit? Do you have any capacitors on the power leads? .1uF AND 10uF?

I personally haven't used this particular RTC but do use the DS1337. I've had 80 of them out in the field and aside from gaining/losing time over a two year period, there hasn't been any problems. I keep three of them at home and only leave them running on a 2032 battery. Then a week or two before the DST changes I power them up and check on the time and it has been fairly good. I cycle the main power on and off several times whenever I can just looking for problems like you mention but haven't encountered anything yet.

Care to share the schematic and some code?

BobK