Koepel:
The Time Library uses "time_t", that is "uint32_t" in the Arduino.
The Time library didn't specify a uint32_t used an unsigned long which can vary depending on CPU.
#if !defined(__time_t_defined) // avoid conflict with newlib or other posix libc
typedef unsigned long time_t;
#endif
On most processors used on Arduinos today, that is 32 bits. (it might be 64 bits on pic32 and intel)
You can define/create your own time_t typedef and defining __time_t_defined
before you include Time.h but it seems like overkill.
--- bill