$ perl -MPOSIX -le'@lt = localtime; $lt[0] -= $lt[0] % 5; print strftime "%Y-%m-%dT%H:%M:%S", @lt' 2009-07-09T12:14:40 $ perl -MPOSIX -le'@lt = localtime; $lt[0] -= $lt[0] % 5; print strftime "%Y-%m-%dT%H:%M:%S", @lt' 2009-07-09T12:14:40 $ perl -MPOSIX -le'@lt = localtime; $lt[0] -= $lt[0] % 5; print strftime "%Y-%m-%dT%H:%M:%S", @lt' 2009-07-09T12:14:45 $ perl -MPOSIX -le'@lt = localtime; $lt[0] -= $lt[0] % 5; print strftime "%Y-%m-%dT%H:%M:%S", @lt' 2009-07-09T12:14:45