NEWS.md
In datey: Exact Date and Duration Arithmetic on an Annual Grid

datey 0.1.1

Fixed undefined behaviour (negation of NA_INTEGER) when parsing durationy from text in C++. Results are unaffected on conforming hardware.

datey 0.1.0

Initial CRAN release.

datey and durationy represent dates and durations on a discrete annual grid, with exact, associative arithmetic (+, -, comparisons, mean(), range(), etc.).
start_day(), mid_day(), end_day() and datey() map calendar year/month/day (and day-fraction), fractional years and Date, POSIXct, POSIXlt to datey.
to_ymdf() and $year, $month, $day and $day_fraction provide the breakdown of a datey into year, month, day and day fraction components.
is_start_day() and is_mid_day() provides checking of datey alignment.
as.double() and as.integer() provide convenient conversion to numeric types as years, with mixed number and datey/durationy arithmetic adhering to the same convention using implicit conversion.
NA_datey_, NA_durationy_ and NA_datey_interval_ provide type-correct NAs, with full is.na()/anyNA() support.
Text parsing and formatting for datey, durationy and datey_interval.
pillar_shaft() methods for readable printing of datey/durationy/ datey_interval columns in tibbles.
is_leap_year() for integer years and dateys.
datey_interval (constructed with datey_interval() or %to%) represents a half-open [start, end) date interval. Operations include:
== and != for equality comparison.
%includes% (or interval_includes()) to test whether an interval contains a datey or numeric value.
& for intersection: returns an empty collapsed interval for adjacent intervals, NA_datey_interval_ for non-intersecting non-adjacent intervals.
is_collapsed(), is_proper() and related predicates.
Constants all_of_time and NA_datey_interval_.
seq() is supported for datey and durationy via a by argument (note: length.out is not supported).