CODEWITHSUNDEEP
rtimelubridate
user1895691
user1895691

Reputation: 81

Seconds since midnight to time of day

There is a post that shows how use lubridate to go from time to seconds since midnight. How about going from seconds since midnight to time of day?

So, instead of using 06:52:32 to get 24752.05, how do I use 24752.05 to get 06:52:32?

Upvotes: 5

Views: 6203

Answers (4)

Dirk is no longer here
Dirk is no longer here

Reputation: 368409

Use as.POSIXct() on the sum of the midnight timestamp and your offset, possibly adjusting by setting TZ.

In my default time zone:

R> as.POSIXct(trunc(Sys.time(), units="days") + 24752.05)
[1] "2013-01-16 06:52:32.04 CST"
R>

Note that the answer (just like the preceding question) can be solved just fine in base R, persistent rumors that every time question has to involve lubridate not withstanding.

Upvotes: 9

Matthew Lundberg
Matthew Lundberg

Reputation: 42669

And of course, you can compute the hours, minutes and seconds directly. This is based on the definition of POSIX time. Midnight always has a time_t value that is divisible by 86400.

x <- 24752.05

paste(sprintf("%02d", floor(x / 3600)),
      sprintf("%02d", floor(x %% 3600 / 60)),
      sprintf("%02d", floor(x %% 60 )),
      sep=":"
)
## [1] "06:52:32"

Upvotes: 3

Matthew Plourde
Matthew Plourde

Reputation: 44614

Another option:

format(as.POSIXct('1900-1-1') + 24752.05, '%H:%M:%S')
# [1] "6:52:32"

Upvotes: 4

Justin
Justin

Reputation: 43265

Using lubridate just for variety:

library(lubridate)

Sys.time() + seconds(24752.05)

or from midnight:

as.Date(Sys.time()) + seconds(24752.05)

Upvotes: 3

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