elapsed: Elapsed dates (monthly, quarterly)

In statar: Tools Inspired by 'Stata' to Manipulate Tabular Data

Elapsed dates (monthly, quarterly)

Description

Elapsed dates (monthly, quarterly)

Usage

as.quarterly(x)

is.quarterly(x)

as.monthly(x)

is.monthly(x)

Arguments

x

a vector

Details

Monthly and quarterly dates are stored as integers, representing the number of elapsed calendar periods since 01/01/1970. As yearmonth and yearqtr the package zoo, these dates are printed in a way that fits their frequency (YYYqq, YYYmMM). The only difference is that, monthly, and quarterly are integers, which removes issues due to floating points (particularly important when merging). This also allows to use arithmetic on perios, ie date + 1 adds one period rather than one day.

Methods to convert from and to Dates or POSIXlt are provided. In particular, you may use lubridate week month and year to extract information from elapsed dates.

Examples

library(lubridate)
library(dplyr)
date <- mdy(c("04/03/1992", "01/04/1992", "03/15/1992"))  
datem <- as.monthly(date)
is.monthly(datem)
as.quarterly(date)
as.character(datem)
datem + 1
df <- tibble(datem)
# filter(df, month(datem) == 1)
seq(datem[1], datem[2])
as.Date(datem)
as.POSIXlt(datem)
as.POSIXct(datem)
week(datem)

statar documentation built on Aug. 19, 2023, 5:09 p.m.