Warm nights percent wrt 90th percentile of reference period
ecatn90p.RdLet infile1 be a time series of the daily minimum temperature TN, and infile2 be the 90th percentile TNn90 of daily minimum temperatures for any period used as reference. Then the percentage of time where TN > TNn90 is calculated. TNn90 is calculated as the 90th percentile of daily minimum temperatures of a five day window centred on each calendar day of a given climate reference period. Note that both TN and TNn90 have to be given in the same units. The date information of a timestep in outfile is the date of the last contributing timestep in infile1.