How to subtract/add days from/to a date?

by

Just subtract a number:

> as.Date("2009-10-01")
[1] "2009-10-01"
> as.Date("2009-10-01")-5
[1] "2009-09-26"

Since the Date class only has days, you can just do basic arithmetic on it.

If you want to use POSIXlt for some reason, then you can use it’s slots:

> a <- as.POSIXlt("2009-10-04")
> names(unclass(as.POSIXlt("2009-10-04")))
[1] "sec"   "min"   "hour"  "mday"  "mon"   "year"  "wday"  "yday"  "isdst"
> a$mday <- a$mday - 6
> a
[1] "2009-09-28 EDT"

More Related Contents:

  1. Convert date-time string to class Date
  2. Find the day of a week
  3. Converting year and month (“yyyy-mm” format) to a date?
  4. Changing date format in R
  5. as.Date with dates in format m/d/y in R
  6. Convert integer to class Date
  7. as.Date returning NA while converting from ‘ddmmmyyyy’
  8. R: How to handle times without dates?
  9. How to subtract years?
  10. How to join (merge) data frames (inner, outer, left, right)
  11. Why are these numbers not equal?
  12. Dynamically select data frame columns using $ and a character value
  13. Error: could not find function … in R
  14. Simultaneously merge multiple data.frames in a list
  15. Count number of rows within each group
  16. Issue when passing variable with dollar sign notation ($) to aes() in combination with facet_grid() or facet_wrap()
  17. How can I remove all duplicates so that NONE are left in a data frame?
  18. Controlling number of decimal digits in print output in R
  19. Round up from .5
  20. Create an empty data.frame
  21. How do you specifically order ggplot2 x axis instead of alphabetical order? [duplicate]
  22. How to flatten / merge overlapping time periods
  23. Export data from R to Excel
  24. Convert a numeric month to a month abbreviation
  25. How to get help in R?
  26. Convert yyyymmdd string to Date class in R
  27. Format date as Year/Quarter
  28. Converting a character string into a date in R
  29. R: How to split a data frame into training, validation, and test sets?
  30. Create a Vector of All Days Between Two Dates

Leave a Comment