Plotted entries from OPSLOG files in ISAAC report DARK_SW_DC, plot 4 (data set p_RMS):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       	MJD-OBS      	values
====================================================
2012-02-06	55964.337644	0.416329290600509
2012-02-07	55965.369912	0.321457240545919
2012-02-08	55966.384569	0.435881492917712
2012-02-09	55967.363475	0.665826853468883