Plotted entries from OPSLOG files in VIMOS report MASK_ZERO, plot 3, data set parY0Q2:

DATE       MJD-OBS      parameter values
==========================================================================
2008-11-20 54790.928079 1064.30306048726	parY0Q2
2008-11-21 54791.890068 1064.38631490264	parY0Q2