Fix to new startR version and manually create obs file_date

inst/doc/usecase/ex3_1_SubseasonalECVHindcast.md

@@ -62,22 +62,36 @@ The time attributes returned by Start() are then used to define the correspondin
 
 ```r
 # Corresponding ERA5 
-dates <- attr(exp, 'Variables')$common$time   #20*4*103=8240  middle day of weekly averages
-file_date <- sapply(dates, format, '%Y%m%d')
-dim(file_date) <- c(length(sdates.seq), 20, 4)
-names(dim(file_date)) <- c('sdate', 'syear', 'time')
-
+## Generate the syears from the sdates.seq
+syears <- t(sapply(sdates.seq, function(x) {
+                   year <- as.numeric(substr(x, 1, 4))
+                   syears <- paste0((year-20):(year-1), substr(x, 5, 8))
+       }))
+names(dim(syears)) <- c('sdate', 'syear')
+
+## Generate the times from the syears
+Sys.setenv(TZ='UTC') # this helps to get UTC times
+times <- lapply(syears, function(x) {
+                x <- as.Date(x, format = "%Y%m%d", tz = "UTC")
+                x <- seq(x, x + 25, by = 'week')
+               format(x, "%Y%m%d")
+              })
+times <- Reduce(c, times)
+dim(times) <- c(time = 4, sdate = 103, syear = 20)
+times <- s2dv::Reorder(times, c(2,3,1))
 
 obs_path <- paste0("/esarchive/recon/ecmwf/era5/weekly_mean/",
                    "$var$_f1h-240x121/$var$_$file_date$.nc")
 
 obs <- Start(dat = obs_path,
              var = 'tas',
-             file_date = file_date,  #  sdate syear  time 
-                                     #    103    20     4 
+             file_date = times,
              latitude = indices(1:121),
              longitude = indices(1:240),
              split_multiselected_dims = TRUE,
+             return_vars = list(latitude = NULL,
+                                longitude = NULL,
+                                time = 'file_date'),
              retrieve = FALSE)
 ```