Whoa, that’s weird. I haven’t seen that on my home units. I can provide you a firmware that allows you to enter an offset in seconds that takes effect every 24 hours. Do you have the ability to flash the firmware? Instructions are in the FAQ.
That would work, but it’s designed to read the value from your 00system/clock.ini file. That way you don’t have to recompile to make changes. I’ve attached a sample clock.ini.