Rob Gee

Apologies if this has already been asked, I can't find anything using search... I have an application running on a rPi model 3B, with a single MCC118 board fitted. OS is raspian V10 (buster). I would like to add an RTC module, and am looking at something like this http://www.cjemicros.co.uk/micros/products/rpirtc.shtml which uses pins 3 and 5 (SDA/SCL) on the expansion connector. There are other modules available, but I suspect most will have I2C connectivity. In theory, provided there isn't an address conflict, it should be possible to do this, provided there are no other pin usage clashes (I don't think there are). The RTC module in the link can be configured for addresses 91,93,97,9F (read) and 90,92,96,9E (write). Would you be able to advise if such a scheme is possible? FYI I don't really want to connect the pi to the WAN (and thus contact a NIST server) if at all possible, it's a corporate wifi network and doing so will create more problems than it solves. Thank you in advance.