Julian-day model ready
Dates represented by astronomical Julian day number, the same internal model Ruby’s Date uses, so arithmetic and conversions match exactly.
go-ruby-date is a pure-Go (no cgo) reimplementation of Ruby's Date and DateTime — built on the astronomical Julian-day model Ruby itself uses, with the configurable Julian→Gregorian reform, full strftime formatting, heuristic parse and format-driven strptime, and ISO week-date and ordinal arithmetic — matching reference Ruby byte-for-byte. It was extracted from rbgo's prelude/internals into a reusable standalone library: no dependency on the Ruby runtime, the dependency runs the other way. It is the date backend for go-embedded-ruby, bound by rbgo as a native module just like go-ruby-regexp and go-ruby-erb — differential-tested against MRI, 100% coverage, CI green across 6 arches and 3 OSes.
Julian→Gregorian reform ready
The configurable reform date (default Italian 1582-10-15), with the missing-days gap handled the way reference Ruby handles it.
strftime formatting ready
The full directive set (%Y %m %d %H %M %S %j %A %a %B %b %z …) producing byte-identical output to MRI’s Date#strftime.
parse & strptime ready
Heuristic Date.parse and format-driven Date.strptime, accepting the same inputs and raising on the same malformed ones as reference Ruby.
Week-date & ordinal arithmetic ready
ISO week-date (%G/%V), ordinal (day-of-year) construction, and day/month arithmetic with Ruby’s rollover semantics.
Differential oracle & coverage ready
A wide date corpus formatted and parsed both here and by the system ruby/date, compared byte-for-byte; 100% coverage, gofmt + go vet clean, green across all six 64-bit Go arches and three OSes.
- ready capability complete (exit criteria met, nothing material left)
- active in progress (substantial work shipped, not yet finished)
- planned not started yet (or downstream by design)
A faithful port of Ruby's Date and DateTime in pure Go, cgo disabled, so it cross-compiles and embeds anywhere. It models dates by Julian day number, honours the Julian→Gregorian reform, formats with the full strftime directive set, parses via parse and strptime, and does ISO week-date and ordinal arithmetic. Validated differentially against the system ruby binary — formatted strings and parsed values compared against Date/DateTime. It is a standalone, reusable module extracted from rbgo's internals, and the date backend for the sibling org github.com/go-embedded-ruby.