Perl created files with future timestamps on FreeBSD 9.3 - perl

Question

I just encountered some strange behavior with Perl 5.16.3 on FreeBSD 9.3-RELEASE-p3. We've got a cron job which runs every five minutes and generates some text status files. I just happened to list the contents of the output directory and saw that the timestamps for some of the files were in the future! The files are created like this:
if (open(OUT, "> $status_file_path")) {
print OUT "$status_info\n";
close OUT;
}
Now, the file handle OUT is used in several places, however it is opened and closed within the same block as shown above. And like I said, out of ten files, only a few had future dates when displayed using ls.
For example, files with the current date had timestamps like 04/02/2015 20:29:46, files with future timestamps were out in November, e.g. 11/10/2015 09:38:41.
What might be going on here?
EDIT
I've got two tests running:
1) a perl script running a loop of 1000 iterations, sleeping a random time up to 10 seconds between iterations, using the open/print/close logic to create an output file and abort the script if the file's modification time is in the future.
2) a cron entry to touch a test file every minute, e.g. touch /home/test/test_file_date_with_cron.txt
TEST RESULTS
Neither of the tests generated output files with a timestamp in the future.
This is scary.
EDIT 2
Here is the filesystem info, the files are written in the /usr directory.
# df -h
Filesystem Size Used Avail Capacity Mounted on
/dev/gpt/gprootfs 2G 133M 1.7G 7% /
devfs 1.0k 1.0k 0B 100% /dev
/dev/gpt/gpusrfs 431G 3.8G 392G 1% /usr
procfs 4.0k 4.0k 0B 100% /proc
EDIT 3
Running the script outside of cron for several hundred iterations didn't duplicate the problem. HOWEVER, I just found some other files, which are created by a CGI script which have the future dates:
-rw-r--r-- 1 test test 5783 Nov 10 2015 Config.xml_20150210_104151
-rw-r--r-- 1 test test 34548 Nov 10 2015 Config2.xml_20150210_104151
-rw-r--r-- 1 test test 6105 Nov 10 2015 Config.xml_20151109_232210
-rw-r--r-- 1 test test 34554 Nov 10 2015 Config2.xml_20151109_232210
-rw-rw-r-- 1 root test 2075 Nov 9 2015 Config.xml_20151109_231055
-rw-rw-r-- 1 root test 1232 Nov 9 2015 Config2.xml_20151109_231055
These are archive files, which get moved and renamed with the file's mtime timestamp. Note that BOTH ls and Perl's stat() function report the future date -- stat() is used to generate the file's timestamp portion of the name.
Looking at the first entry, ls reports "Nov 10 2015", whereas when the CGI script processed it, Perl's stat() reported "20150210_104151", i.e. "Feb 02 2015" which is most likely correct.
Further down, we see ls showing "Nov 10 2015" and stat() reported "20151109_232210", i.e. "Nov 09 2015".

Answer 1

Finding those additional archived config files helped me track down the cause, which was as others have suggested, that the system date and timezone changed.
From: 1447147328 and America/Adak
To: 1426637771 and America/New_York
What was throwing me off, was that I thought the cron script wrote ALL of the output files each time it executes, but that's not the case. The files have different "refresh intervals".