Plotted entries from OPSLOG files in ISAAC report DISPERS, plot 4 (data set p_L_SK_AR):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       	MJD-OBS      	values
====================================================
2013-10-21	56587.625344810000000	6.93844482204345

Plotted entries from OPSLOG files in ISAAC report DISPERS, plot 4 (data set p_L_SK_XE):
(DATE changes at 21:00 UT or MJD-OBS = xxx.875)
DATE       	MJD-OBS      	values
====================================================
2013-10-21	56587.625344810000000	6.98320671062414