time library

Can someone tell me what kind of variable is the time_t? I know its unix time but i eant to know if this can work: time_t t = someVariable (unsigned long type)?
I know they are both 32bit.
Thank you

Can someone tell me what kind of variable is the time_t?

time_t IS the type, just like int, float, char, uint8_t, etc.

i eant to know if this can work

So, try it. The Arduino won't bite you. Neither will the IDE.