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Date Utilities

Source: R/utilities.R
fg_date_utilities.Rd

COnverts a generic relative string defining one or two endpoints to exact dates or datestrings

Usage

gendtstr(x, today = Sys.Date(), rtn = "dtstr")

narrowbydtstr(
  xin,
  dtstr = "",
  includetoday = TRUE,
  windowdays = 0,
  invert = FALSE,
  addindicator = FALSE
)

extenddtstr(
  instr,
  begchg = 0,
  endchg = 0,
  mindt = NULL,
  maxdt = NULL,
  rtn = "",
  rtnstyle = "string"
)

Arguments

x

String describing generalized date as of today

today

Default Sys.Date()

rtn

string describing what to do: (list,datelist,fromtoday,totoday)

xin

Input data.frame or data.table with a Date column

dtstr

Generalized Date string of the form <yyyy-mm-dd>::<yyyy-mm-dd> or e.g. -3m::

includetoday

(Default: TRUE) pass either today Sys.Date() or Sys.Date()-1 to gendtstr

windowdays

(Default: 0)Number of additional days to add at beginning of series

invert

(Default: FALSE) Return dates not in dtstr

addindicator

(Default: FALSE) Returns original dataset with logical variable inrange if date is in desired range.

instr

Input generalized date string, data.table or xts dataset

begchg

(Default: 0) Number of calendar days to extend beginning

endchg

(Default: 0) Number of calendar days to extend end

mindt

Minimum date to return

maxdt

Maximum date to return

rtnstyle

REturn datestring or list

Value

an exact start date startdt and an exact end date enddt, in the following forms: If rtn="list" returns c(startdt,enddt), if rtn="first" then startdt, if rtn="days then an integer number of days from startdt to today otherwise (by default) "startdt::enddt"

Same form as xin, i.e. a data.table or data.frame

character string or list with new dates

Examples

gendtstr("-3m::")
#> [1] "2026-07-07::2026-10-07"
gendtstr("-2y::-3m",today=as.Date("2025-03-15"))
#> [1] "2023-03-15::2024-12-15"
narrowbydtstr(eqtypx,"-2m::-1m")
#> Key: <date>
#>           date   EEM    IBM    QQQ   TLT
#>         <Date> <num>  <num>  <num> <num>
#>  1: 2026-08-07 65.64 235.59 723.03 82.76
#>  2: 2026-08-10 65.17 236.31 720.87 82.06
#>  3: 2026-08-11 65.43 238.42 718.45 82.19
#>  4: 2026-08-12 66.46 235.98 723.70 82.11
#>  5: 2026-08-13 66.68 237.14 732.07 82.59
#>  6: 2026-08-14 66.61 234.32 731.07 82.04
#>  7: 2026-08-17 67.32 228.85 729.87 81.35
#>  8: 2026-08-18 65.34 232.67 717.51 81.66
#>  9: 2026-08-19 66.11 237.16 716.08 83.02
#> 10: 2026-08-20 66.62 233.69 710.93 82.34
#> 11: 2026-08-21 67.12 235.68 713.44 82.05
#> 12: 2026-08-24 66.11 231.04 706.32 82.56
extenddtstr("-2m::-1m")
#> [1] "2026-08-07::2026-09-07"
extenddtstr("-2m::-1m",begchg=-10,endchg=5)
#> [1] "2026-07-28::2026-09-12"