I have a question about how to construct a "standardized timeline" across planets under special relativity.

I get that the passage of time is relative to an inertial frame of reference, but as I understand, it's still possible to calculate what the perceived passage of time will be from other inertial reference frames.

If we assume that planets move at a constant velocity relative to one another, it seems like you could just pick an arbitrary inertial reference frame [Earth's timescale] and, when writing a universal history, refer to all events as occurring relative to this timescale.

I understand there's issues with this [i.e. events that appear simultaneous on earth won't be simultaneous from other reference frames], but there would still be a "standard" reference people could refer to.

Am I understanding this correctly? What other issues would there be with creating a "standardized timeline" under SR?