Extract year from eventDate

Source: R/bdc_year_from_eventDate.R

This function extracts a four-digit year from unambiguously interpretable collecting dates.

bdc_year_from_eventDate(data, eventDate = "eventDate")

Arguments

data

A data frame containing a column with event date information.

eventDate

Numeric or date. The column with event date information.

Value

A data.frame containing the column "year". Year information is returned only if "eventDate" can be unambiguously interpretable from "eventDate". Years in the future (e.g., 2050) are returned as NA as well as years before 1600, which is the lower limit for collecting dates of biological specimens.

See also

Other time: bdc_eventDate_empty(), bdc_year_outOfRange()

Examples

collection_date <- c(
  NA, "31/12/2015", "2013-06-13T00:00:00Z", "2019-05-20",
  "", "2013", "0001-01-00", "20", "1200"
)
x <- data.frame(collection_date)

bdc_year_from_eventDate(data = x, eventDate = "collection_date")
#> 
#> bdc_year_from_eventDate:
#> Four-digit year were extracted from 6 records.
#>        collection_date year
#> 1                 <NA>   NA
#> 2           31/12/2015 2015
#> 3 2013-06-13T00:00:00Z 2013
#> 4           2019-05-20 2019
#> 5                        NA
#> 6                 2013 2013
#> 7           0001-01-00    1
#> 8                   20   NA
#> 9                 1200 1200