Julian dates

The Julian calendar is the calendar used by the Roman Empire, and takes its name from Julius Caesar, who introduced it in 46 BC. It is still used as a religious calendar in parts of the Eastern Orthodox Church.

Usage

julian_date(year = integer(), month = integer(), day = integer())

as_julian(date)

Arguments

year

A numeric vector of years

month

A numeric vector of months

day

A numeric vector of days

date

Vector of dates on some calendar

Value

A julian vector object

See also

cal_julian

Examples

as_date("2016-01-01", calendar = cal_julian)
#> <julian[1]>
#> [1] 2015-Dec-19
as_date(Sys.Date(), calendar = cal_julian)
#> <julian[1]>
#> [1] 2025-Jun-17
tibble::tibble(
  x = seq(as.Date("2025-01-01"), as.Date("2025-12-31"), by = "day"),
  y = as_date(x, calendar = cal_gregorian),
  z = as_date(x, calendar = cal_julian)
)
#> # A tibble: 365 × 3
#>    x                    y           z
#>    <date>           <Gre>       <Jul>
#>  1 2025-01-01 2025-Jan-01 2024-Dec-19
#>  2 2025-01-02 2025-Jan-02 2024-Dec-20
#>  3 2025-01-03 2025-Jan-03 2024-Dec-21
#>  4 2025-01-04 2025-Jan-04 2024-Dec-22
#>  5 2025-01-05 2025-Jan-05 2024-Dec-23
#>  6 2025-01-06 2025-Jan-06 2024-Dec-24
#>  7 2025-01-07 2025-Jan-07 2024-Dec-25
#>  8 2025-01-08 2025-Jan-08 2024-Dec-26
#>  9 2025-01-09 2025-Jan-09 2024-Dec-27
#> 10 2025-01-10 2025-Jan-10 2024-Dec-28
#> # ℹ 355 more rows
new_date(year = 2025, month = 4, day = 19:30, calendar = cal_julian)
#> <julian[12]>
#>  [1] 2025-Apr-19 2025-Apr-20 2025-Apr-21 2025-Apr-22 2025-Apr-23 2025-Apr-24
#>  [7] 2025-Apr-25 2025-Apr-26 2025-Apr-27 2025-Apr-28 2025-Apr-29 2025-Apr-30
julian_date(2025, 4, 19:30)
#> <julian[12]>
#>  [1] 2025-Apr-19 2025-Apr-20 2025-Apr-21 2025-Apr-22 2025-Apr-23 2025-Apr-24
#>  [7] 2025-Apr-25 2025-Apr-26 2025-Apr-27 2025-Apr-28 2025-Apr-29 2025-Apr-30
as_julian("2016-01-01")
#> <julian[1]>
#> [1] 2015-Dec-19
as_julian(Sys.Date())
#> <julian[1]>
#> [1] 2025-Jun-17
tibble::tibble(
  x = seq(as.Date("2025-01-01"), as.Date("2025-12-31"), by = "day"),
  y = as_julian(x)
)
#> # A tibble: 365 × 2
#>    x                    y
#>    <date>           <Jul>
#>  1 2025-01-01 2024-Dec-19
#>  2 2025-01-02 2024-Dec-20
#>  3 2025-01-03 2024-Dec-21
#>  4 2025-01-04 2024-Dec-22
#>  5 2025-01-05 2024-Dec-23
#>  6 2025-01-06 2024-Dec-24
#>  7 2025-01-07 2024-Dec-25
#>  8 2025-01-08 2024-Dec-26
#>  9 2025-01-09 2024-Dec-27
#> 10 2025-01-10 2024-Dec-28
#> # ℹ 355 more rows