Create or decompose a datey using calendar year, month, day and day fraction

The lengths of vector arguments must be multiples of each other.

to_ymdf() returns a list of the year, month, day and day_fraction breakdown of a datey, where

• year is an integer in [1000,3000],

• month is an integer in [1,12],

• day is an integer in [1,N], where N is the number of days in the month specified by year and month, and

• day_fraction is a double in [0,1) representing the fraction of the day, where e.g. 0 means the start and 0.5 means the middle of the day.

Alternatively, if you want only one or two components, use the list-like syntax $year, $month, $day or $day_fraction.

If the datey was constructed using end_day or day_fraction = 1 then to_ymdf() will return the start of the next day with day_fraction = 0.

from_ymdf() creates a datey from a calendar year, month, and day fraction. In practice, prefer one of start_day(), mid_day() or end_day() for clarity.

Usage

to_ymdf(datey)

from_ymdf(year, month, day, day_fraction, strict = TRUE)

Arguments

datey

A datey to be deconstructed.

year

Calendar year. Valid years are from 1000 to 3000 (although the only legal date in 3000 is the start of 3000-01-01). If provided as double then these must be integers.

month

Month number in calendar year, with 1 representing January. If provided as double then these must be integers.

day

Day number in month, with 1 representing the first day of the month. If provided as double then these must be integers.

day_fraction

The fraction of the day, in [0,1]. 0 means the start of the day, 0.5 means the middle of the day, and 1 means the end of the day (which is identical to the start of the next day).

strict

How to handle invalid arguments. If strict is TRUE – the default – then execution is stopped. If strict is FALSE then NA is returned.

NA arguments result in NA (and do not stop execution) regardless of strict.

Value

from_ymdf returns a vector of datey. to_ymdf returns a list of integer vector year, integer vector month, integer vector day, and double vector day_fraction.

See also

Use datey() to create a datey direct from years or a base R date.

Use the syntax $year, $month, $day or $day_fraction to extract one component at a time.

Examples

  t <- from_ymdf(2001, 2, 3, 0.5)
  t
#> [1] 2001-02-03.5
  to_ymdf(t)
#> $year
#> [1] 2001
#> 
#> $month
#> [1] 2
#> 
#> $day
#> [1] 3
#> 
#> $day_fraction
#> [1] 0.5
#> 
  t$year
#> [1] 2001
  t$month
#> [1] 2
  t$day
#> [1] 3
  t$day_fraction
#> [1] 0.5