#zdat (zcalib by M.Zolliker 2018)
#time since midnight, R ref, R meas, sigma
43896.34	35612.4	64453.2	5.65296382
46026.31	31259	55711.3	21.4508974
52221.48	26848.54	46903.73	20.4987514
55795.44	21993.52	37573.63	4.27190941
57758.31	17881.26	29833.82	2.0071273
59720.48	14613.21	23854.64	1.54014285
61696.31	11937.86	19066.51	0.846811667
70424.32	78.9198	95.9028	0.00152839785
74944.34	71.4823	86.7112	0.00123125952
79283.38	65.1019	78.8428	0.00128685664
82813.39	62.0355	75.0651	0.000842021377
85856.33	60.3783	73.0256	0.000777174369