What moritz said, and if you want to keep what is before and after the T, split into an array: 
use warnings;
use strict;

while (<DATA>) {
    my @items = split /T/;
    print "@items";
}

__DATA__
2010-12-01T20:15:20.000+01:00
2010-12-01T21:10:18.000+01:00
2010-12-01T21:15:40.000+01:00
2010-12-01T23:28:04.000+01:00
2010-12-01T20:16:33.000+01:00

[download]
prints... 
2010-12-01 20:15:20.000+01:00
2010-12-01 21:10:18.000+01:00
2010-12-01 21:15:40.000+01:00
2010-12-01 23:28:04.000+01:00
2010-12-01 20:16:33.000+01:00

[download]

In reply to Re: split line from one point by toolic
in thread split line from one point by Anonymous Monk

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