将12小时的日期/时间转换为24小时的日期/时间 [英] Convert 12-hour date/time to 24-hour date/time
问题描述
我有一个制表符分隔文件,其中每个记录都有12小时格式的时间戳记字段:
mm / dd / yyyy hh :mm:ss [AM | PM]。
我需要快速将这些字段转换为24小时制:
mm / dd / yyyy HH:mm:ss。
最好的方法是什么?我正在Windows平台上运行,除了通常的Windows工具之外,我还可以访问sed,awk,perl,python和tcl。
使用Perl和手工制作的正则表达式,而不是像strptime这样的设施:
#!/ bin / perl -w
while(<))
{
#对于不使用前导零的日期时间,请改用此正则表达式:
#(?:\d {1,2} / \d {1,2} / \d {4})(\d {1,2})(?:: \d\d:\d\d) (AM | PM)
while(m%(?: \d\d / \d\d / \d {4})(\d\d)(? \\ d \d:\d\d)(AM | PM)%)
{
我的$ hh = $ 1;
$ hh - = 12 if($ 2 eq'AM'& $ hh == 12);
$ hh + = 12 if($ 2 eq'PM'& $ hh!= 12);
$ hh = sprintf%02d,$ hh;
#对于不使用前导零的日期时间,请使用此正则表达式:
#(\d {1,2} / \d {1,2} / \d {4 })(\d {1,2})(:\d\d:\d\d)(?:AM | PM)
s%(\d\d / \ d \d / \d {4})(\d\d)(:\d\d:\d\d)(?:AM | PM)%$ 1 $ hh $ 3%;
}
print;
}
这很奇怪,但也可以每行转换多个时间戳。 >
请注意,AM / PM到24小时的转换不是微不足道的。
- 12:01 - > 00:01
- 12:01 PM - > 12:01
- 01:30 AM - > 01 :30
- 01:30 PM - > 13:30
现在测试: / p>
perl ampm-24hr.pl<< ;!
12/24/2005 12:01:00 AM
09/22/1999 12:00:00 PM
12/12/2005 01:15:00 PM
01 / 01/2009 01:56:45 AM
12/30/2009 10:00:00 PM
12/30/2009 10:00:00 AM
!
12/24/2005 00:01:00
09/22/1999 12:00:00
12/12/2005 13:15:00
01/01/2009 01:56:45
12/30/2009 22:00:00
12/30/2009 10:00:00
添加:
在什么是在AM / PM时间和JavaScript之间的24小时时间内转换的简单方法,为转换提供了一种替代算法:
$ hh =($ 1%12)+(($ 2 eq'AM')?0:12);
只需一个测试...可能更整洁。
I have a tab delimited file where each record has a timestamp field in 12-hour format:
mm/dd/yyyy hh:mm:ss [AM|PM].
I need to quickly convert these fields to 24-hour time:
mm/dd/yyyy HH:mm:ss.
What would be the best way to do this? I'm running on a Windows platform, but I have access to sed, awk, perl, python, and tcl in addition to the usual Windows tools.
Using Perl and hand-crafted regexes instead of facilities like strptime:
#!/bin/perl -w
while (<>)
{
# for date times that don't use leading zeroes, use this regex instead:
# (?:\d{1,2}/\d{1,2}/\d{4} )(\d{1,2})(?::\d\d:\d\d) (AM|PM)
while (m%(?:\d\d/\d\d/\d{4} )(\d\d)(?::\d\d:\d\d) (AM|PM)%)
{
my $hh = $1;
$hh -= 12 if ($2 eq 'AM' && $hh == 12);
$hh += 12 if ($2 eq 'PM' && $hh != 12);
$hh = sprintf "%02d", $hh;
# for date times that don't use leading zeroes, use this regex instead:
# (\d{1,2}/\d{1,2}/\d{4} )(\d{1,2})(:\d\d:\d\d) (?:AM|PM)
s%(\d\d/\d\d/\d{4} )(\d\d)(:\d\d:\d\d) (?:AM|PM)%$1$hh$3%;
}
print;
}
That's very fussy - but also converts possibly multiple timestamps per line.
Note that the transformation for AM/PM to 24-hour is not trivial.
- 12:01 AM --> 00:01
- 12:01 PM --> 12:01
- 01:30 AM --> 01:30
- 01:30 PM --> 13:30
Now tested:
perl ampm-24hr.pl <<!
12/24/2005 12:01:00 AM
09/22/1999 12:00:00 PM
12/12/2005 01:15:00 PM
01/01/2009 01:56:45 AM
12/30/2009 10:00:00 PM
12/30/2009 10:00:00 AM
!
12/24/2005 00:01:00
09/22/1999 12:00:00
12/12/2005 13:15:00
01/01/2009 01:56:45
12/30/2009 22:00:00
12/30/2009 10:00:00
Added:
In What is a Simple Way to Convert Between an AM/PM Time and 24 hour Time in JavaScript, an alternative algorithm is provided for the conversion:
$hh = ($1 % 12) + (($2 eq 'AM') ? 0 : 12);
Just one test...probably neater.
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