Plotted entries from OPSLOG files in NACO report DAILY_DARKRON, plot 3 (data set ronFNS1_HC):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       	MJD-OBS      	values
====================================================
2013-05-15	56428.479312600000000	1.35869678957821
2013-05-16	56429.369909360000000	1.34245906848782
2013-05-17	56430.372909740000000	1.2940730714289
2013-05-18	56431.365791840000000	1.31195407803211