In zchmielewska/actuary: Tools for Actuaries

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

library(actuary)

Reference dates functions

Purpose

Business reports are prepared once a month, once a quarter or once a year. Analysts often compare business results against previous periods. First and last days of a given period are of special significance for reporting.

The dref_ prefix stands for date reference functions. The functions with the dref_ prefix return a reference date to the chosen date.

Functions

The functions work within three types of periods:

• month
• quarter
• year

The functions return one of the four type of reference dates:

• first day
• first working day
• last day
• last working day

The names of functions combine the dref_ prefix and the first letters of the chosen reference date.

For example, dref_fdoy() returns the first day of year.

The table summarizes all reference date functions.

| | of month | of quarter | of year | |-------------------|----------------|----------------|----------------| | first day | dref_fdom() | dref_fdoq() | dref_fdoy() | | first working day | dref_fwdom() | dref_fwdoq() | dref_fwdoy() | | last day | dref_ldom() | dref_ldoq() | dref_ldoy() | | last working day | dref_lwdom() | dref_lwdoq() | dref_lwdoy() |

All functions take the argument date, which is the base date. The functions return the result in reference to the base date. The functions always work within a specific period: a month, a quarter or an year.

Monthly periods

The reference dates in the image below can be retrieved with the following functions:

• dref_fdom() - dark blue
• dref_fwdom() - light blue
• dref_ldom() - light green
• dref_lwdom() - dark green

The base date has been marked with orange.

knitr::include_graphics("img/dref_monthly.png")

Quarterly periods

The reference dates in the image below can be retrieved with the following functions:

• dref_fdoq() - dark blue
• dref_fwdoq() - light blue
• dref_ldoq() - light green
• dref_lwdoq() - dark green

The base date has been marked with orange.

Watch out! The first day of a year is the same as the first working day of a year. The last day of a year is the same as the last working day of a year. Hence, the same day is marked with two colors (darker and lighter).

knitr::include_graphics("img/dref_quarterly.png")

Yearly periods

The reference dates in the image below can be retrieved with the following functions:

• dref_fdoy() - dark blue
• dref_fwdoy() - light blue
• dref_ldoy() - light green
• dref_lwdoy() - dark green

The base date has been marked with orange.

Watch out! The first day of a year is the same as the first working day of a year. The last day of a year is the same as the last working day of a year. Hence, the same day is marked with two colors (darker and lighter).

knitr::include_graphics("img/dref_yearly.png")

zchmielewska/actuary documentation built on Feb. 5, 2020, 6:43 p.m.