Yeah, timespec (or time_interval) is a proper way to go, but it is quite a pain to work with -- you need a library even if you just want to subtract the numbers

Yeah, timespec (or time_interval) is a proper way to go, but it is quite a pain to work with -- you need a library even if you just want to subtract the numbers. On the other hand, floating-point time is pretty common in scripting languages -- for example Python has time.time(); ruby has Time.now.to_f. It is not perfect, but great for smaller scripts: fool proof (except for the precision loss), roundtrips via any serialization format, and easy to understand. And no timezone problems at all!