rollback: Rollback of months

In DTSg: A Class for Working with Time Series Data Based on 'data.table' and 'R6' with Largely Optional Reference Semantics

Rollback of months

Description

Generating regular sequences of time with the help of seq.POSIXt can have undesirable effects. This function “first advances the month without changing the day: if this results in an invalid day of the month, it is counted forward into the next month”. Monthly or yearly sequences starting at the end of a month with 30 or 31 days (or 29 in case of a leap year) therefore do not always fall on the end of shorter months. rollback fixes this by counting the days of affected months backwards again.

Usage

rollback(.dateTime, periodicity)

Arguments

.dateTime	A POSIXct vector.
periodicity	A character string specifying a multiple of month(s) or year(s). See seq.POSIXt for further information.

Value

Returns a POSIXct vector.

Examples

# rollback monthly time series
by <- "1 month"
rollback(
  .dateTime = seq(
    from = as.POSIXct("2000-01-31", tz = "UTC"),
    to = as.POSIXct("2000-12-31", tz = "UTC"),
    by = by
  ),
  periodicity = by
)

DTSg documentation built on Sept. 28, 2023, 1:06 a.m.