Plotted entries from OPSLOG files in MIDI report DETLIN_cust, plot 9 (data set A0_PRISM_ops):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       	MJD-OBS      	values
====================================================
2012-05-21	56069.350324	4731.498535
2012-05-22	56070.352905	4812.727051
2012-05-23	56071.348148	4742.881348