將GMT從GMT轉換爲EST

Question

我試圖將格林威治標準時間提供的日期標記的字符串值轉換爲EST（或GMT -5）中的正確時間。我沒有掌握如何通過GMT將值傳遞給函數並返回EST值。

源值是這樣的：2015年1月1日17時05分53秒

，我需要回到2015年1月1日12時05分53秒

讚賞任何幫助...

謝謝！

Answer 1

使用日期時間::格式:: Strptime獲得DateTime對象，然後設置遵循了時區爲「UTC」是「-0500」，讓您的轉換

use DateTime::Format::Strptime; 

my $parser = DateTime::Format::Strptime->new(pattern => "%Y-%m-%d %H:%M:%S"); 
$datetime=$parse->parse_datetime("2015-01-01 17:05:53"); 

$datetime->set_time_zone("UTC"); 
$datetime->set_time_zone("-0500"); 

print $datetime->strftime("%Y-%m-%d %H:%M:%S"); 

欲瞭解更多信息，請參閱CPAN文檔：

http://search.cpan.org/~drolsky/DateTime-Format-Strptime-1.56/lib/DateTime/Format/Strptime.pm

http://search.cpan.org/~drolsky/DateTime-1.18/lib/DateTime.pm

Answer 2

#!/usr/bin/perl 

use strict; 
use warnings; 
use 5.010; 

# Use DateTime::Format::Strptime to parse your date string 
use DateTime::Format::Strptime; 

my $format = '%F %T'; # This is the format of your date/time strings 
my $from_tz = 'UTC'; 
my $to_tz = '-0500'; 

# Create a parser object that knows the strings it is given are in UTC 
my $parser = DateTime::Format::Strptime->new(
    pattern => $format, 
    time_zone => $from_tz, 
); 

my $in_date = '2015-01-01 17:05:53'; 

# Use the parser to convert your string to a DateTime object 
my $dt = $parser->parse_datetime($in_date); 

# Use DateTime's set_time_zone() method to change the time zone 
$dt->set_time_zone($to_tz); 

# Print the (shifted) date/time string in the same format 
say $dt->strftime($format);