Plotted entries from OPSLOG files in ISAAC report DARK_SW_DC, plot 1 (data set p_DARK):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       MJD-OBS      values
====================================================
2010-03-15 55271.423137 295.7666626
2010-03-16 55272.418193 296.1666768
2010-03-17 55273.431179 293.3999939
2010-03-18 55274.436050 294.700002