With v4.2, calChecker keeps a memory about open NOK/MISS issues beyond the canonical 7 days, up to the configured value for the calibration&issue memory (lower right corner). This is implemented both for 'science' and for 'cal4cal'.
The following key is used to define a MIDI setup:
ins.gris.name (PRISM or GRISM)
-- day time calibrations: they are used only for HC purposes
-- night time calibrations:
For the SCIPHOT mode, the KAPPA MATRIX (CAL_SP_KAP) is valid for the full night
For both modes (HIGHSENS and SCIPHOT), the calibrator (CAL_SP_FRT or CAL_HS_FRT) is valid for -1.2 / +1.2 hour