How to create a range of dates in R

Question

From two integers (1, 5) one can create a range in the following way

1:5

[1] 1 2 3 4 5

How can you make a range of dates if you are give two dates ("2014-09-04 JST", "2014-09-11 JST")

The output must be

[1] ("2014-09-04 JST", "2014-09-05 JST", "2014-09-06 JST", "2014-09-07 JST", "2014-09-08 JST")

Answer 1

Does this help?

seq(as.Date("2014/09/04"), by = "day", length.out = 5)
# [1] "2014-09-04" "2014-09-05" "2014-09-06" "2014-09-07" "2014-09-08"

edit: adding in something about timezones

this works for my current timezone

seq(c(ISOdate(2014,4,9)), by = "DSTday", length.out = 5) 
#[1] "2014-04-09 08:00:00 EDT" "2014-04-10 08:00:00 EDT" "2014-04-11 08:00:00 EDT" "2014-04-12 08:00:00 EDT"
#[5] "2014-04-13 08:00:00 EDT"

edit2:

OlsonNames()  # I used this to find out what to write for the JST tz - it's "Japan"

x <- as.POSIXct("2014-09-04 23:59:59", tz="Japan")
format(seq(x, by="day", length.out=5), "%Y-%m-%d %Z")

# [1] "2014-09-04 JST" "2014-09-05 JST" "2014-09-06 JST" "2014-09-07 JST" "2014-09-08 JST"

Answer 2

To get a sequence of dates ( days, weeks,.. ) using only start and end dates you can use:

seq(as.Date("2014/1/1"), as.Date("2014/1/10"), "days”)

[1] "2014-01-01" "2014-01-02" "2014-01-03" "2014-01-04" "2014-01-05" "2014-01-06" "2014-01-07"
[8] "2014-01-08" "2014-01-09" "2014-01-10”

Answer 3

Here's an answer, admittedly worse than @jalapic's, that doesn't use seq and instead uses a for loop:

date1 <- "2014-09-04"
date2 <- "2014-09-11"
dif <- as.numeric(abs(as.Date(date1) - as.Date(date2)))
dates <- vector()
for (i in 1:dif) {
  date <- (as.Date(date1) + i)
  dates <- append(dates, date)
}
# [1] "2014-09-05" "2014-09-06" "2014-09-07" "2014-09-08" "2014-09-09" "2014-09-10" "2014-09-11

Answer 4

here's a shot though the timezone JST isn't recognized by my system

d1<-ISOdate(year=2014,month=9,day=4,tz="GMT")
seq(from=d1,by="day",length.out=5)
[1] "2014-09-04 12:00:00 GMT" "2014-09-05 12:00:00 GMT" "2014-09-06 12:00:00 GMT" "2014-09-07 12:00:00 GMT" "2014-09-08 12:00:00 GMT"

Answer 5

While using seq(date1, date2, "days") is by far the better option in nearly all cases, I'd just like to add, that the following works too, if you need a range of dates that are n_number of days from a date:

1:10 + as.Date("2020-01-01")

# [1] "2020-01-02" "2020-01-03" "2020-01-04" "2020-01-05"
# [5] "2020-01-06" "2020-01-07" "2020-01-08" "2020-01-09"
# [9] "2020-01-10" "2020-01-11"