The PCF8583 data sheet on page 21 has a detailed way to tune the on board oscillator with the 1 Hz output. Do not know if you have tried it. We normally are able to get around a few seconds of deviation per day - OK for our application. But you are right in one respect - these fellows act crankily at times and the only way to solve the problem is change the fellow.

One standard method is to find out the deviation per day and have an algorithm to apply the correction once in 24 Hrs. In certain cases this is quite acceptable as the trend of variation is constant - you either loose or gain .

But if you start to get a variation of 2minutes / day, then first that has to be settled.

Raghu