Jusep:
To get help about RTC's you should post more information about the model you are planning to use, so that people can look for the datasheet and more documentation.I have never worked with an RTC, so I am afraid I cannot help with this doubt.
Good luck!
i bought everything so cheap that doesn't even have a model, since i am just prototyping...
but it look like this. i make it work using wire and RTClib tho
jremington:
The RTC cannot be the master. It can only respond to requests for data.However, it can initiate an interrupt, to signal alarms.
i tried to google but i cant put all together, i needed that answer, short and precise xD, so if cant be master, i only have to set one of the arduinos to the clock thing, i hope setting a master will solve a lot of more problems that i got with my project 