search for: ddawn

Hi, I would appreciate if somebody could help me with this small issue... I have a dataframe like this (originaly has more than 100 000 rows): > subz jul time dtime fix ddawn ddusk day 101608 15006 2011-02-01 19:14:49 19.24694 noon 7.916667 19.88333 1 101609 15006 2011-02-01 19:24:49 19.41361 midnight 7.916667 19.56667 1 101610 15006 2011-02-01 19:24:49 19.41361 noon 7.916667 19.88333 1 101611 15006 2011-02-01 19:34:49 19.58028 midnight 7.916667 19.5666...