Providing Fractions of a second to DateTime?

cmv has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks-

I'm parsing a logfile that gives me Timezone, Month, Day, Year, and the number of milliseconds since midnight. I would like to create a timestamp string down to the milliseconds of the form:

mm/dd/yyyy hh:mm:ss.xxx

I fancy using DateTime to help me out with this, but I'm having trouble figuring out how to generate and provide the fraction of a second to it. I am forced to use perl5.8 - any help is very much appreciated!

Thanks

-Craig

Here is my current code that does not handle fractions of a second:

use strict;
use warnings;

# Get Data...
my ($tZone, $pMonth, $pDay, $pYear, $pStart) = qw(-04:00 05 30 2012 50
+460904);
print STDERR "tZone=$tZone pMonth=$pMonth pDay=$pDay pYear=$pYear pSta
+rt=$pStart\n";

use DateTime;

# Start from midnight...
my $dt = DateTime->new(year=>$pYear, month=>$pMonth, day=>$pDay, hour=
+>00, minute=>00, second=>00, time_zone=>$tZone);

# Add in milliseconds since midnight (pStart)...
$dt->add(seconds=>int($pStart/1000));

my $timestamp = $dt->strftime('%D %T.%3N');
print STDERR "timestamp=$timestamp\n";
[download]

Comment on Providing Fractions of a second to DateTime? Download Code

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Re: Providing Fractions of a second to DateTime? by tobyink (Canon) on Jun 12, 2012 at 14:41 UTC
`use DateTime; my $timezone = 'UTC'; my $year = 2012; my $month = 6; my $day = 12; my $millisecond = 3600000; # 1.00 am my $dt = DateTime->new( year => $year, month => $month, day => $day, hour => 0, minute => 0, second => 0, nanosecond => 0, time_zone => $timezone, )->add( nanoseconds => ($millisecond * 1_000_000), ); print $dt;` [download] `perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'`	[reply] [d/l]
Re^2: Providing Fractions of a second to DateTime? by cmv (Chaplain) on Jun 12, 2012 at 15:00 UTC
Thank you ++tobyink - this is it!	[reply]
Re: Providing Fractions of a second to DateTime? by ansh batra (Friar) on Jun 12, 2012 at 14:13 UTC
`use DateTime; $dt = DateTime->new( year => 1964, month => 10, day => 16, hour => 16, minute => 12, second => 47, nanosecond => 500000000, #see this time_zone => 'Asia/Taipei', );` [download] this example is given on CPAN	[reply] [d/l]
Re^2: Providing Fractions of a second to DateTime? by cmv (Chaplain) on Jun 12, 2012 at 14:25 UTC
Thanks for the pointer to nanosecond. I originally saw that and tried various things that made sense to me. For instance: `my $dt = DateTime->new(year=>$pYear, month=>$pMonth, day=>$pDay, millisecond=>$pStart, time_zone=>$tZone);` [download] Well, that didn't work, since it doesn't take millisecond as an argument to new, so I tried converting $pStart to nanoseconds-since-midnight and substituting in that, but alas - it seems that the nanosecond value is only for providing the intra-second-delta. See my above response to what I think I need to do. I'm hoping someone will show me a better way...	[reply] [d/l]
Re^3: Providing Fractions of a second to DateTime? by ansh batra (Friar) on Jun 12, 2012 at 14:32 UTC
`$dt = DateTime->new( year=>2003, month=>6, day=>12, hour=>7, minute=>22, second=>12, millisecond=>345, microsecond=>678, nanosecond=>901 );` [download] this should also work and use `$dt->millisecond()` for your calculations refer cpan	[reply] [d/l] [select]
Re^4: Providing Fractions of a second to DateTime? by tobyink (Canon) on Jun 12, 2012 at 14:35 UTC
Re^5: Providing Fractions of a second to DateTime? by ansh batra (Friar) on Jun 12, 2012 at 14:44 UTC
Re: Providing Fractions of a second to DateTime? by daxim (Curate) on Jun 12, 2012 at 13:55 UTC
DateTime::HiRes	[reply]
Re^2: Providing Fractions of a second to DateTime? by cmv (Chaplain) on Jun 12, 2012 at 14:12 UTC
Thanks for the pointer to HiRes, but I don't think that helps. I already have the number of milliseconds since midnight from the log. What I think I need to do is to get DateTime to tell me the number of milliseconds from midnight to 14:01:00.000 on this date, then subtract that from the total number of milliseconds since midnight, then tell DateTime to add that result to the original timestamp that I calculated. When I read this back, it sounds too complicated. I must be missing something...	[reply]