r - Generate an ordered series of datetime

Question

I am working in R.

I have to generate a series of dates and times. In particular, I would like to have two data points per day, hence to assign twice each date with a different time, for instance:

"2001-05-13 00:00:00"
"2001-05-13 12:00:00"
"2001-05-14 00:00:00"
"2001-05-14 12:00:00"

I found the following code to produce a series of dates:

seq(as.Date("2000/1/1"), as.Date("2003/1/1"), by = 0.5)

Nevertheless, even if I set the by = 0.5, the code returns only a date , not a datetime.

Any idea how to produce a series of datetimes?

Answer 1

as.Date will produce only dates, use as.POSIXct to produce date-time.

seq(as.POSIXct("2000-01-01 00:00:00", tz = 'UTC'), 
    as.POSIXct("2003-01-01 00:00:00", tz = 'UTC'), by = '12 hours')

# [1] "2000-01-01 00:00:00 UTC" "2000-01-01 12:00:00 UTC"
# [3] "2000-01-02 00:00:00 UTC" "2000-01-02 12:00:00 UTC"
# [5] "2000-01-03 00:00:00 UTC" "2000-01-03 12:00:00 UTC"
# [7] "2000-01-04 00:00:00 UTC" "2000-01-04 12:00:00 UTC"
# [9] "2000-01-05 00:00:00 UTC" "2000-01-05 12:00:00 UTC"
#[11] "2000-01-06 00:00:00 UTC" "2000-01-06 12:00:00 UTC"
#[13] "2000-01-07 00:00:00 UTC" "2000-01-07 12:00:00 UTC"
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