C:\Old_Data\perlp>perl t33.pl
2011-01-13 21:00:00  -+-  2011-01-14 09:00:00
Avg of 9 lines   1.33478   1.33509   1.33458   1.33482
2011-01-14 22:00:00  -+-  2011-01-15 10:00:00
Avg of 1 lines   1.33524   1.33551   1.33512   1.33549