Plotted entries from OPSLOG files in UVES report BIAS_struct_Y_DHC, plot 6 (data set psREDU_2x2_50_P):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       	MJD-OBS      	values
====================================================
2012-05-13	56061.401239	0.2904
2012-05-14	56062.399241	0.2936
2012-05-15	56063.456329	0.277
2012-05-16	56064.632984	0.2894
2012-05-17	56065.462553	0.2796
2012-05-18	56066.622087	0.276
2012-05-19	56067.469902	0.3558
2012-05-20	56068.482271	0.3578
2012-05-21	56069.463481	0.2784
2012-05-22	56070.466142	0.3578
2012-05-23	56071.410990	0.3629