Plotted entries from OPSLOG files in ISAAC report DARK_SW_DC, plot 3 (data set p_R_UR):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       	MJD-OBS      	values
====================================================
2013-05-12	56425.429161750000000	2.46769580160753
2013-05-12	56425.469484540000000	2.50189367487007