[BUGZILLA #16621] strptime(, tz=x) returns inconsistent gmtoff and tzone properties

[MichaelChirico]

When the format provided to strptime() includes an offset (%z) element AND the tz argument, the resulting POSIXlt value has a gmtoff that conflicts with the tzone attribute.

For example:

t <- strptime('24/Aug/2014:17:57:26 +0200', '%d/%b/%Y:%H:%M:%S %z', 

+ tz = 'Pacific/Honolulu')

t

[1] "2014-08-24 05:57:26"

str(unclass(t))

List of 11
$ sec : num 26
$ min : int 57
$ hour : int 5
$ mday : int 24
$ mon : int 7
$ year : int 114
$ wday : int 0
$ yday : int 235
$ isdst : int 0
$ zone : chr ""
$ gmtoff: int 7200

• attr(*, "tzone")= chr [1:3] "Pacific/Honolulu" "HST" "HDT"

The time fields seem to be correct, at 17:57 in the GMT+2 time zone: it's indeed 5:57 in Hawaii, but the gmt offset 7200 refers to the GMT+2 timezone, not Hawaii, whose offset is -10 hours, or -36000 seconds.

Do I misunderstand the purpose of the gmtoff value or is something that should be fixed? If so, will happily submit patch.

str(R.Version())

List of 14
$ platform : chr "x86_64-pc-linux-gnu"
$ arch : chr "x86_64"
$ os : chr "linux-gnu"
$ system : chr "x86_64, linux-gnu"
$ status : chr ""
$ major : chr "3"
$ minor : chr "2.0"
$ year : chr "2015"
$ month : chr "04"
$ day : chr "16"
$ svn rev : chr "68180"
$ language : chr "R"
$ version.string: chr "R version 3.2.0 (2015-04-16)"
$ nickname : chr "Full of Ingredients"

---

METADATA

• Bug author - Alex Bertram
• Creation time - 2015-12-04 12:49:25 UTC
• Bugzilla link
• Status - UNCONFIRMED
• Alias - None
• Component - Accuracy
• Version - R 3.2.2
• Hardware - x86_64/x64/amd64 (64-bit) Linux
• Importance - P5 enhancement
• Assignee - R-core
• URL -