These operations allow users to add or subtract dates messydate objects. Messydate objects include incomplete or uncertain dates, ranges of dates, negative dates, and date sets.
# S3 method for mdate
+(e1, e2)
# S3 method for mdate
-(e1, e2)An mdate or date object.
An mdate, date, or numeric object. Must be a scalar.
A messydates vector
# \donttest{
d <- as_messydate(c("2008-03-25", "-2012-02-27", "2001-01?", "~2001",
"2001-01-01..2001-02-02", "{2001-01-01,2001-02-02}",
"2008-XX-31", "..2002-02-03", "2001-01-03..", "28 BC"))
tibble::tibble(date = d, add = d + 1, subtract = d - 1)
#> # A tibble: 10 × 3
#> date add subtract
#> <mdate> <mdate> <mdate>
#> 1 2008-03-25 2008-03-26 2008-03-24
#> 2 -2012-02-27 -2012-02-26 -2012-02-28
#> 3 2001-01? 2001-01-02..2001-02-01 2000-12-31..2001-01-30
#> 4 ~2001 2001-01-02..2002-01-01 2000-12-31..2001-12-30
#> 5 2001-01-01..2001-02-02 2001-01-02..2001-02-03 2000-12-31..2001-02-01
#> 6 {2001-01-01,2001-02-02} {2001-01-02,2001-02-03} {2000-12-31,2001-02-01}
#> 7 2008-XX-31 2008-02-01 2008-XX-30
#> 8 ..2002-02-03 ..2002-02-04 ..2002-02-02
#> 9 2001-01-03.. 2001-01-04.. 2001-01-02..
#> 10 -0028 -27-12-31..-28-12-30 -28-01-02..-29-01-01
tibble::tibble(date = d, add = d + "1 year", subtract = d - "1 year")
#> # A tibble: 10 × 3
#> date add subtract
#> <mdate> <mdate> <mdate>
#> 1 2008-03-25 2009-03-25 2007-03-26
#> 2 -2012-02-27 -2011-02-27 -2013-02-26
#> 3 2001-01? 2002-01 2000-01-02..2000-02-01
#> 4 ~2001 2002 2000-01-02..2000-12-31
#> 5 2001-01-01..2001-02-02 2002-01-01..2002-02-02 2000-01-02..2000-02-03
#> 6 {2001-01-01,2001-02-02} {2002-01-01,2002-02-02} {2000-01-02,2000-02-03}
#> 7 2008-XX-31 2009-XX-30 2007-XX-31
#> 8 ..2002-02-03 ..2003-02-03 ..2001-02-03
#> 9 2001-01-03.. 2002-01-03.. 2000-01-04..
#> 10 -0028 -27-01-01..-28-01-01 -28-12-31..-29-12-31
as_messydate("2001-01-01") + as_messydate("2001-01-02..2001-01-04")
#> 'mdate' chr "2001-01-01..2001-01-04"
as_messydate("2001-01-01") + as_messydate("2001-01-03")
#> 'mdate' chr "{2001-01-01,2001-01-03}"
as_messydate("2001-01-01..2001-01-04") - as_messydate("2001-01-02")
#> [[1]]
#> 'mdate' chr "{2001-01-01,2001-01-03..2001-01-04}"
#>
#as_messydate("2001-01-01") - as_messydate("2001-01-03")
# }