README.md

In edgararuiz/gregorian: Manages gregorian dates and calculations

gregorian

Provides a robust date object. It also provides date calculation functions that work on top of the new object. Many of the functions seamlessly convert Date and character objects into the new gregorian_date object.

Problem

as.Date("-99-7-12")

Error in charToDate(x) : 
  character string is not in a standard unambiguous format

Installation

And the development version from GitHub with:

# install.packages("devtools")
devtools::install_github("edgararuiz/gregorian")

Gregorian object

library(gregorian)
as_gregorian("-99-7-12")
#> Friday July 12, 100 BCE

born <- as_gregorian("-99-7-12")

str(born)
#> List of 7
#>  $ year        : num 100
#>  $ month       : int 7
#>  $ day         : int 12
#>  $ bce         : logi TRUE
#>  $ day_name    :List of 2
#>   ..$ name  : chr "Friday"
#>   ..$ number: num 5
#>  $ astronomical: chr "-99-07-12"
#>  $ full_date   : chr "Friday July 12, 100 BCE"
#>  - attr(*, "class")= chr "gregorian_date"

get_date()
#> Monday May 13, 2019 CE

Date calculations

diff_days(born, get_date())
#> [1] 773524

diff_dates(born, get_date())
#> $years
#> [1] 2117
#> 
#> $months
#> [1] 10
#> 
#> $days
#> [1] 1

diff_calendar(born, get_date())
#> $years
#> [1] 2117
#> 
#> $months
#> [1] 9
#> 
#> $days
#> [1] 32

add_days(get_date(), 365)
#> Tuesday May 12, 2020 CE

Leap Year

is_leap_year(2012)
#> [1] TRUE

is_leap_year(2019)
#> [1] FALSE

Day Rotation

# Sunday plus one day (1 == Monday)
day_rotation(1, 7, 6) + 1
#> [1] 1

# Sunday plus 100 days (2 == Tuesday)
day_rotation(100, 7, 6) + 1
#> [1] 2

In the tidyverse

library(dplyr)

dt <- tribble(~dates,
        as.Date("12/12/2014"),
        as.Date("1/1/1") - 1000,
        as.Date("1/1/1") - 365
        )

dt
#> # A tibble: 3 x 1
#>   dates     
#>   <date>    
#> 1 12-12-20  
#> 2 -2-04-07  
#> 3 0-01-02

library(purrr)

dt %>%
  mutate(new_date = map(dates, as_gregorian))
#> # A tibble: 3 x 2
#>   dates      new_date            
#>   <date>     <list>              
#> 1 12-12-20   <S3: gregorian_date>
#> 2 -2-04-07   <S3: gregorian_date>
#> 3 0-01-02    <S3: gregorian_date>

dt %>%
  mutate(new_date = map_chr(dates, ~as_gregorian(.x)$full_date))
#> # A tibble: 3 x 2
#>   dates      new_date                   
#>   <date>     <chr>                      
#> 1 12-12-20   Thursday December 20, 12 CE
#> 2 -2-04-07   Tuesday April 7, 3 BCE     
#> 3 0-01-02    Sunday January 2, 1 BCE

dt %>%
  mutate(
    today_diff = map2_dbl(dates, Sys.Date(), diff_days)
    ) 
#> # A tibble: 3 x 2
#>   dates      today_diff
#>   <date>          <dbl>
#> 1 12-12-20       732820
#> 2 -2-04-07       738191
#> 3 0-01-02        737556

edgararuiz/gregorian documentation built on June 4, 2019, 11:48 a.m.