CFtime 1.4.1

• Method slab() has an additional argument rightmost.closed to indicate if
  the upper extreme value should be included in the result.
• Fixed bounds information on CFtime instances returned from methods indexOf()
  and slab().
• Several minor code improvements.

CFtime 1.4.0

• Bounds that define intervals around offsets can be associated with a CFtime
  instance and retrieved as raw offset values or as formatted timestamps.
• Methods that subset a CF time series (e.g. CFfactor(), cut(), slab())
  now have an attribute "CFtime" (among possible others) that describes the "time"
  dimension of the analysis result applying the subset. In other words, if CFtime
  instance 'Acf' describes the temporal dimension of data set 'A' and a factor 'Af'
  is generated from 'Acf', then Bcf <- attr(Af, "CFtime") describes the temporal
  dimension of the result of, say, B <- apply(A, 1:2, tapply, Af, FUN).
• New indexOf() method added that returns the indices of supplied timestamps
  in a CFtime instance, optionally with a fractional part. This can be used to
  extract specific time steps, or to interpolate between time steps using the
  fractional part, from the time dimension of the data set associated with the
  CFtime instance. A vector of indices (e.g. referring to slices of the data set)
  can also be supplied, in which case valid indices are returned, with the new
  CFtime instance.
• New cut() method added to generate a factor, similar to cut.POSIXt() but with
  some differences in the arguments.
• CFfactor() now supports a period "quarter", for calendar quarters.
• format() method added that generates a character vector of timestamps for the
  offsets in a CFtime instance. The format is specified using the flags used in
  strptime(), with some limitations. In particular, locale-specific formatting is
  limited to month names and no weekday information can be generated. The range()
  method has a new "format" parameter to support the same functionality and timestamps
  can also be generated for the extremes of the bounds, if set.
• as.character() and length() methods added that return a vector of timestamps
  or the number of offsets in a CFtime instance, respectively.
• Several functions have been renamed (most notably CFtimestamp() to
  as.timestamp(), CFcomplete() to is_complete(), CFrange() to the standard
  generic method range(), and CFsubset() to slab()) to be more consistent
  with the R universe. The original functions are now flagged as being deprecated.
  Some datum functions (deep down where regular mortals do not dwell) have been
  deleted.
• Time zone designator "UTC" accepted when parsing timestamps to offsets.
• Minor code fixes, see GitHub commits.
• Documentation updated, with description of new functions.

CFtime 1.3.0

Changes since release 1.2.0:

• Two CFtime instances can be added if they have compatible calendars and units.
  The earlier origin is preserved in the result and offsets from the later instance
  are incremented by the appropriate amount. As before, in the result offsets are
  in the order of the specified CFtime instances.
• A new function CFsubset() can be used to retrieve a logical vector that indicates
  which time steps in a CFtime instance fall between two timestamps. This is useful
  to slice data during reading from file or analysis.
• Time zone information is managed at the level of the datum. If a vector of character
  timestamps is parsed and found to have different time zones, a warning is generated.
• Much reduced memory footprint.
• Minor code fixes, see GitHub commits.
• Codecov.io test coverage monitoring added.
• Documentation updated, with description of new functions.

CFtime 1.2.0

Changes since release 1.1.0:

• Datum units "years" and "months" added. While these units are discouraged by
  the CF Metadata Conventions due to their problematic definition, there are quite
  a few data sets out there that use these units nonetheless. For this reason,
  reading existing files with such datum units is supported (converting offsets to
  time elements is easy) but parsing timestamps is not (calculating offsets from
  time elements is possible but tedious and slow). Should there be a definite need,
  open an issue on GitHub and make a very good case why this functionality is
  required.
• CFresolution() returns the average separation between elements in a time series,
  in units of the datum.
• CFcomplete() indicates if the time series is complete, meaning that there are
  no gaps in the time series. This also works for time series with a somewhat
  variable length such as monthly data with a "days" datum unit. This works for
  all but the most exotic time dimension constructions.
• CFtimestamp() produces a timestamp for all midnight values if the datum unit is
  "hours", "minutes" or "seconds". The "time" format has been removed. For "standard",
  "gregorian" and "proleptic_gregorian" calendars output can be generated as POSIXct
  by specifying the new argument asPOSIX = TRUE -- defaults to FALSE, the
  previous behaviour so the API is not broken.
• Minor documentation updates.
• Assorted minor code fixes, see GitHub commits.

CFtime 1.1.0

Changes since release 1.0.0:

• CFtime() can now also be invoked with a vector of character timestamps as offsets, or
  with a single timestamp to create a complete time series from the datum to the
  indicated timestamp.
• CFtimestamp() can now automatically select the best format for the time series.
• New CFfactor_units() and CFfactor_coverage() functions. CFfactor_units() will
  tell you how many time units compose every level of a factor. CFfactor_coverage()
  computes the actual or relative number of time units in the factor levels from the
  time series in a CFtime instance with which the factor was created. This will
  enable you to assess the completeness of your time series (and perhaps filter out
  factor levels below a certain coverage threshold) and it can be useful in computing
  absolute values from average values, as is often useful when computing anomalies.
• Global constants are now defined in a package environment, CFt.
• Documentation expanded, updated and fixed.
• Assorted minor code fixes, see GitHub commits.

CFtime 1.0.0

• Initial CRAN submission.
• This version supports all CF Metadata Conventions calendars for use with
  climate change projection data.
• You can create timestamps from the offsets in the files and create factors
  that greatly simplify working with climate change data.