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
====================================================
2012-02-06	55964.337644	326.033335367839
2012-02-07	55965.369912	327.333343505859
2012-02-08	55966.384569	328.299997965495
2012-02-09	55967.363475	328.166666666667