era 0.5.0

• New yr_sort() function for chronological ordering of year vectors (#44)
• New yr_earliest(), yr_latest(), and yr_range() functions for chronological extremes of year vectors (#43)

era 0.4.1

This patch fixes a malfunctioning test that was causing CRAN checks to fail. There are no significant changes.

• Fixed malfunctioning check #41

era 0.4.0

era 0.4.0 was released on CRAN on 2022-03-09.

• New eras:
  • Anno Mundi (Hebrew calendar)
• New year units:
  • Sidereal, tropical, and anomalistic astronomic years #15
  • Hebrew lunisolar years
• Changes to existing eras:
  • More precise epoch value for Hijri eras: 621.5394 instead of 622.
  • More precise epoch value for Nowruz (Solar Hijri) eras: 621.2218 instead of 622.
• Fixed recurring issues related to the absence of a year 0 in BCE/CE #4
• this_year() now considers the current date, returns a floored integer (i.e. the actual current calendar year), and is vectorised over era.
• Added pillar printing methods for era (#33) and era_year (#34) in tibbles
• Class constructors era() and yr() now return a zero-length vector when called with no arguments (instead of an error), allowing them to be used as prototypes
• era_yr objects can now be cast to character vectors (e.g. as.character(yr(1, "BP")))
• Combining otherwise equivalent eras with different names or labels with c() now triggers a warning (#27), consistent with combining them using arithmetic (#3)
• The era package no longer exports magrittr's pipe operator (%>%)

era 0.3.1

First CRAN release.

There is only one minor change from v0.3.0:

• Fixed moved link in README.md

era 0.3.0

Second beta / CRAN pre-release

• Added new era definitions:
  • Islamic calendars (Lunar Hijri, Solar Hijri).
  • Julian calendar
• Reworked era definition scheme:
  • Unit is now represented by the era_year class, which describes its length in solar days as well as its name. Added functions for constructing and working with era_year objects: era_year(), is_era_year(), era_year_label(), era_year_days().
  • Direction is now coded as 1 ("forwards") or -1 ("backwards"). The previous character arguments still work but are deprecated.
  • Equality tests for eras now only check significant parameters (i.e. not "label" or "name"), allowing for coercion between functionally equivalent eras, e.g. yr(1, "BP") + yr(1, "cal BP") now works (with a warning) (#3).
• Improved yr_transform():
  • Can now convert between eras with different year units (#25).
  • Now has a precision argument, allowing the result to be rounded (#23).
• era and yr objects are now validated when constructed, using new functions validate_era()/is_valid_era() and validate_yr()/is_valid_yr() (#7 and #8).
• Minor changes/bug fixes:
  • Added this_year(), which returns the current year as a yr object.
  • era(NA) now returns an error, not a vector of all standard eras (#20).
  • All era arguments in functions can now accept a character vector (#20)
  • era(<era>) now returns an era with the same parameters (to enable the above)
  • Various additions to make the coercion hierarchy for era_yrs more consistent; most notably, the common prototype of era_yr, integer, and double, is now era_yr.
  • Fixed printing of NA eras (#9)
  • Errors now use the rlang format and are in general more informative (#26 and #28)

era 0.2.0

First beta release, including:

• S3 vector class yr (era_yr) representing years with an era
  • yr() constructor
  • Functions for getting and setting the era of a yr object: yr_era(), yr_era()<- and yr_set_era()
  • Format and print methods for yrs
  • Vector arithmetic methods for yrs
• S3 record class era representing an era definition
  • era() constructor
  • Format and print methods for eras
  • Getter functions for era parameters: era_label(), era_name(), era_epoch(), era_unit(), era_scale(), era_direction()
  • eras() defining standard eras
• yr_transform() function for converting years between eras
• Function documentation and introductory vignette: vignette("era")
• A NEWS.md file to track changes to the package.