Plotted entries from OPSLOG files in MIDI report DSPTRN_2.0, plot 6 (data set TRANS_GRISM_SIV_ops):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       	MJD-OBS      	values
====================================================
2012-02-08	55966.382431	0.590403
2012-02-09	55967.392928	0.590709
2012-02-10	55968.451447	0.590517