nyx-space
Display should print in Gregorian in the Epoch's time scale
At the moment, fmt::Display of an Epoch will print it in UTC. Only the fmt::Debug prints it with the current time scale. This is needlessly confusing. For example, in Nyx, we often initialize epochs in TAI, but hifitime will then print them as UTC, making it hard to keep track when reading logs.
If a user wishes to print in another time scale, they should have that option though (the in_time_scale does not convert to another time scale!).
Actually
the in_time_scale does not convert to another time scale!
is the only confusing thing here. We should have an explicit method to simply set the time scale, or either perform a real translation/conversion
maybe have in_time_scale perform the proper conversion, and have a with_timecale() to simply set the timescale as is, would make more sense. Anyways, has to be clearly explained in the docs
This fix must ensure that UTC epochs are correctly printed too, cf. the error in formatting of the UTC date in https://github.com/nyx-space/hifitime/discussions/292 .