Jalaali (Shamsi) calendar for elixir (Persian calendar)

I disagree, since in most ecosystems converting to/from UNIX is common but i didn’t found any that commonly uses Day number. did you?

I actually don’t see any downsides in functionalities of both implementations. both of them will work. i am just saying using UNIX as base timestamp is common in most ecosystems. so for supporting more calendars on Elixir we only need to port libraries that were previously implemented and battle tested by other big communities.
AND we can convert UNIX to day number easily with a very low cost. but reversing that result in loosing of precision. right?

Lets move to this topic: Calendars & Calendar Conversions