Plotted entries from OPSLOG files in VIMOS report BIASRMS, plot 8, data set parQ4hi:

DATE       MJD-OBS      parameter values
==========================================================================
2008-11-19 54789.593795 3.24634836007021	parQ4hi
2008-11-20 54790.551116 3.24642766428598	parQ4hi
2008-11-21 54791.518803 3.25670863679763	parQ4hi