Can now() roll over just like millis()? I'm using now() and millis() to trigger events after a certain time has passed.
I am aware, and it's also easily found on the web, that millis() rolls over after a certain time has passed and for code that has to run indefinitely you have to handle this.

However I am not aware of if now() can do the same at some point. I mean it does count the seconds from the 1.1.1970 so just regarding this fact, it should not roll over. However, just like millis() this has to be counted somewhere no? How does it work?
now() is a function that is specific to Intel Curie based boards. 

It returns an unsigned long (which on a 32-bit system is the same as an unsigned int) and so can provide the number of seconds since 1/1/1970 up until the year 2106, at which point it will roll over.

If you plan on having your system run continuously for more than the next 88 years you will have to deal with that rollover correctly, including:


Using subtraction to "wrap around" your calculations
Not trying to calculate any periods longer than 136 years