Totally! Just pointing out that unix timestamps don't solve everything (even before getting to relativity).
International Atomic Time (TAI), which differs by UTC by 37 seconds since it doesn't count leap seconds, solves everything I know of. Although the clocks aren't in a single reference frame, the procedure for measuring their differences and averaging them to define TAI is well defined and so sets an objective standard for "what time is it on Earth".
International Atomic Time (TAI), which differs by UTC by 37 seconds since it doesn't count leap seconds, solves everything I know of. Although the clocks aren't in a single reference frame, the procedure for measuring their differences and averaging them to define TAI is well defined and so sets an objective standard for "what time is it on Earth".