Plotted entries from OPSLOG files in NACO report DAILY_DARKRON, plot 5 (data set darkFNS3_HC):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       	MJD-OBS      	values
====================================================
2013-05-14	56427.484741860000000	30.4375
2013-05-15	56428.471805480000000	20.8125
2013-05-16	56429.362420940000000	26.28125
2013-05-17	56430.365421450000000	28.03125