days = c()
dt_ref = as.POSIXlt(data$getTime(index)[1]) #first date-time of current day
day_ref = dt_ref$wday #1=monday, ..., 6=saturday, 0=sunday
month_ref = as.POSIXlt(data$getTime(index)[1])$mon+1 #month in 1...12
days = c()
dt_ref = as.POSIXlt(data$getTime(index)[1]) #first date-time of current day
day_ref = dt_ref$wday #1=monday, ..., 6=saturday, 0=sunday
month_ref = as.POSIXlt(data$getTime(index)[1])$mon+1 #month in 1...12