| Subject: | Incorrect Time-Zone for Standard Time During Cross Over (Fall Back) |
When converting a time-stamp into a date-time string with a time zone
(either %Z or %z), it does not get the time-zone correct for what looks
like the hour after the fall-back when hour gets repeated. This is
compounded by str2time not returning the same time-stamp even using the
incorrect time-zone.
My system time is set to America/Los_Angeles and no TZ variable is set.
Here is demonstration of it failing:
#!/usr/bin/perl
use strict;
use Date::Format;
use Date::Parse;
foreach my $ts ( 1352019262, 1352021105, 1352024705 ){
my $dt = time2str( "%Y-%m-%d %X %Z", $ts );
my $ts_new = str2time( $dt );
printf "%d -> %s -> %d (%s)\n", $ts, $dt, $ts_new, ( $ts == $ts_new
? "OK" : "ERROR" );
}
Which produces:
1352019262 -> 2012-11-04 01:54:22 PDT -> 1352019262 (OK)
1352021105 -> 2012-11-04 01:25:05 MST -> 1352017505 (ERROR)
1352024705 -> 2012-11-04 02:25:05 PST -> 1352024705 (OK)
This is happening with DateTime v. 1.20 in Fedora 16 and a much older
version on CentOS 5.8.
A C program works fine:
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
int
main(int argc, char *argv[])
{
char outstr[200];
char format[] = "%Y-%m-%d %X %Z";
time_t t;
struct tm *tmp;
t = (time_t)atoi(argv[1]);
tmp = localtime(&t);
if (tmp == NULL) {
perror("localtime");
exit(EXIT_FAILURE);
}
if (strftime(outstr, sizeof(outstr), format, tmp) == 0) {
fprintf(stderr, "strftime returned 0");
exit(EXIT_FAILURE);
}
printf("%d is \"%s\"\n", t, outstr);
exit(EXIT_SUCCESS);
} /* main */
gcc ./time-test.c -o time-test
./time-test 1352019262
1352019262 is "2012-11-04 01:54:22 PDT"
1352021105 is "2012-11-04 01:25:05 PST"
1352024705 is "2012-11-04 02:25:05 PST"