[Rant] Chronodot giving me garbage

I love the Chronodot for its accuracy, but its reliability leaves something to be desired.

From an info page:

The ChronoDot RTC is an extremely accurate real time clock module, based on the DS3231 temperature compensated RTC (TCXO).

So the problem I am going to mention is likely because of the DS3231 chip itself rather than the Chronodot module.

I have used the Chronodot in two clocks my father and I have built. When this chip works, it works pretty well -- certainly better than, for example, the timekeeping of an ordinary cheap wall clock.

The problem is that it is too easy to mess up. Irregularities in the power supply shouldn't, but occasionally do, screw up the time. When this happens, you might get '00-1-1 00:00:00, or you might just get garbage (once I think I got '00-1-5 something).

I will digress for a moment to talk about a very different module, namely, the DHT temperature and humidity sensor. The information that the Arduino reads from this sensor includes a checksum, clearly for the purpose of telling good data apart from garbage transmissions or line noise.

As the DS3231 has no support for a checksum, I have resorted to using the day of the week as a makeshift "checksum". (Example: Thursday, May 10, 2015 is garbage; Thursday, May 14, 2015 is good.) This approach isn't perfect, but it is better than nothing, and I have found it useful.

The problem is, if you know that the date and time are bad, how to get the correct
date and time. So far, I have resorted to having the clock either use 12:00 (like an old VCR) or show a message "PLEASE SET THE DATE AND TIME". But I really don't like this: after all, the clock is supposed to provide me with the correct date and time, not the other way around.

I would much prefer that the RTC guard itself against getting messed up. What I mean is, I would like an RTC that knows the difference between line noise and a command to set itself. If the command to set the time were to contain a checksum, that would be a step in the right direction. Also, it should manage its power supply better. It has a backup battery good for 7 or 8 years; is there any reason for there to be interruptions of any sort in its timekeeping?