diff --git a/R/CST_SaveExp.R b/R/CST_SaveExp.R
index 2130aadde6838b61c040860be99af73f2e88d018..dfcc77995ece1eb622b5e1af6e1518dde75a1b35 100644
--- a/R/CST_SaveExp.R
+++ b/R/CST_SaveExp.R
@@ -291,11 +291,6 @@ SaveExp <- function(data, destination = "./", Dates = NULL, coords = NULL,
             "set as FALSE.")
     single_file <- FALSE
   }
-  if (single_file) {
-    warning("Parameter 'single_file' is TRUE. Time values saved in the NetCDF ", 
-            "file may not be consistent for all the start dates. ", 
-            "Further development is needed, sorry for the inconvinience.")
-  }
   # extra_string
   if (!is.null(extra_string)) {
     if (!is.character(extra_string)) {
@@ -629,6 +624,7 @@ SaveExp <- function(data, destination = "./", Dates = NULL, coords = NULL,
       defined_dims <- c(new_dim, defined_dims)
       extra_info_dim[[dat_dim]] <- list(Datasets = paste(Datasets, collapse = ', '))
     }
+    first_sdate <- last_sdate <- NULL
     if (!is.null(Dates)) {
       # sdate definition
       sdates <- Subset(Dates, along = ftime_dim, 1, drop = 'selected')
@@ -639,15 +635,48 @@ SaveExp <- function(data, destination = "./", Dates = NULL, coords = NULL,
       names(new_dim) <- sdate_dim
       defined_dims <- c(defined_dims, new_dim)
       extra_info_dim[[sdate_dim]] <- list(sdates = paste(sdates, collapse = ', '))
+      first_sdate <- sdates[1]
+      last_sdate <- sdates[length(sdates)]
       # ftime definition
-      ftime_dates <- Subset(Dates, along = sdate_dim, 1, drop = 'selected')
-      differ <- as.numeric((ftime_dates - ftime_dates[1])/3600)
-      # DOUBT HERE: which values we take? # FIX Dates[1] for single_file = TRUE
-      dim_time <- list(ncdim_def(name = ftime_dim, units = paste('hours since', paste(sdates, collapse = ', ')),
-                                 vals = differ, calendar = 'proleptic_gregorian',
-                                 longname = ftime_dim, unlim = TRUE))
-      names(dim_time) <- ftime_dim
-      defined_dims <- c(defined_dims, dim_time)
+      Dates <- Reorder(Dates, c(ftime_dim, sdate_dim))
+      differ_ftime <- apply(Dates, 2, function(x){as.numeric((x - x[1])/3600)})
+      dim(differ_ftime) <- dim(Dates)
+      differ_ftime_subset <- Subset(differ_ftime, along = sdate_dim, 1, drop = 'selected')
+      if (all(apply(differ_ftime, 1, function(x){length(unique(x)) == 1}))) {
+        if (all(diff(differ_ftime_subset/24) == 1)) {
+          # daily values
+          dim_time <- list(ncdim_def(name = ftime_dim, units = 'days',
+                                     vals = differ_ftime_subset/24, calendar = 'proleptic_gregorian',
+                                     longname = ftime_dim, unlim = TRUE))
+          names(dim_time) <- ftime_dim
+          defined_dims <- c(defined_dims, dim_time)     
+        } else if (all(diff(differ_ftime_subset/24) %in% c(28, 29, 30, 31))) {
+          # monthly values
+          dim_time <- list(ncdim_def(name = ftime_dim, units = 'months',
+                                     vals = round(differ_ftime_subset/730), 
+                                     calendar = 'proleptic_gregorian',
+                                     longname = ftime_dim, unlim = TRUE))
+          names(dim_time) <- ftime_dim
+          defined_dims <- c(defined_dims, dim_time)   
+        } else {
+          # other frequency
+          dim_time <- list(ncdim_def(name = ftime_dim, units = 'hours',
+                                     vals = differ_ftime_subset, 
+                                     calendar = 'proleptic_gregorian',
+                                     longname = ftime_dim, unlim = TRUE))
+          names(dim_time) <- ftime_dim
+          defined_dims <- c(defined_dims, dim_time)  
+        }
+      } else {
+        warning("Time steps are not equal for all start dates. Only ", 
+                "forecast time values for the first start date will be saved ", 
+                "correctly.")
+        dim_time <- list(ncdim_def(name = ftime_dim, units = paste('hours since', paste(sdates, collapse = ', ')),
+                                   vals = differ_ftime_subset, calendar = 'proleptic_gregorian',
+                                   longname = ftime_dim, unlim = TRUE))
+        names(dim_time) <- ftime_dim
+        defined_dims <- c(defined_dims, dim_time)
+      }
     }
 
     # var definition
@@ -713,9 +742,16 @@ SaveExp <- function(data, destination = "./", Dates = NULL, coords = NULL,
       defined_vars <- c(defined_vars, new_var)
     }
     if (is.null(extra_string)) {
-      file_name <- paste0(paste(c(varname), collapse = '_'), ".nc")
+      gsub("-", "", first_sdate)
+      file_name <- paste0(paste(c(varname, 
+                                  gsub("-", "", first_sdate), 
+                                  gsub("-", "", last_sdate)), 
+                                  collapse = '_'), ".nc")
     } else {
-      file_name <- paste0(paste(c(varname), collapse = '_'), "_", extra_string, ".nc")
+      file_name <- paste0(paste(c(varname, 
+                                  gsub("-", "", first_sdate), 
+                                  gsub("-", "", last_sdate), 
+                                  extra_string), collapse = '_'), ".nc")
     }
     full_filename <- file.path(destination, file_name)
     file_nc <- nc_create(full_filename, defined_vars)
diff --git a/tests/testthat/test-CST_SaveExp.R b/tests/testthat/test-CST_SaveExp.R
index 987f41cfe884ca2d5fbbfa56df5137e91ef249bb..cb028d6a42ad8803cf8bce745ad1ae8cd7eb1cf1 100644
--- a/tests/testthat/test-CST_SaveExp.R
+++ b/tests/testthat/test-CST_SaveExp.R
@@ -201,10 +201,6 @@ test_that("1. Input checks", {
   #           dat_dim = NULL, var_dim = NULL, single_file = TRUE),
   #   "Parameter 'varname' is NULL. It will be assigned to 'X'.",
   #   "Parameter 'metadata' is not provided so the metadata saved will be incomplete.",
-  #   paste0("Parameter 'single_file' is TRUE. Time values saved in the NetCDF ", 
-  #           "file may not be consistent for all the start dates. ", 
-  #           "Further development of the function is needed, sorry ", 
-  #           "for the inconvinience."),
   #   paste0("Spatial coordinate names do not match any of the names accepted by ",
   #          "the package."),
   #   "Detected unknown dimension: test"