Well, the general idea seems usable enough; X time units from a specific reference point. Conversion is then done to whatever local time-keeping system you migh

Well, the general idea seems usable enough; X time units from a specific reference point. Conversion is then done to whatever local time-keeping system you might have. Leap seconds are based on conditions here on Earth and wouldn't really be needed on Mars or Venus. They might have different peculiarities though, and they wouldn't be usable on Earth. In that situation, a single point of reference would be useful for conversions.