diff --git a/gga_get_data.py b/gga_get_data.py
index 20ec80d37f1b1449fd216ae616d8f594976e952a..8bc092de24dbcbef9d5a5725637fdeae2841d719 100755
--- a/gga_get_data.py
+++ b/gga_get_data.py
@@ -91,6 +91,12 @@ class GetData(speciesData.SpeciesData):
 
         logging.info("src_data directory tree generated for %s" % self.full_name)
 
+    def get_last_modified_time_string(self, filePath):
+        # give the last modification date for the file, with format '20190130'
+        lastModifiedTimestamp = os.path.getmtime(filePath)
+        lastModifiedTimeStructure = time.localtime(lastModifiedTimestamp)
+        lastModifiedDate = time.strftime("%Y%m%d", lastModifiedTimeStructure)
+        return lastModifiedDate
 
     def get_source_data_files_from_path(self):
         """
@@ -137,7 +143,7 @@ class GetData(speciesData.SpeciesData):
                 elif k in annotation_datasets:
                     dataset_fname = ""
                     if k == "gff_path":
-                        dataset_fname = "{0}_OGS{1}.gff".format(self.dataset_prefix, self.ogs_version)
+                        dataset_fname = "{0}_OGS{1}_{2}.gff".format(self.dataset_prefix, self.ogs_version, self.get_last_modified_time_string(os.path.abspath(v)))
                     elif k == "transcripts_path":
                         dataset_fname = "{0}_OGS{1}_transcripts.fasta".format(self.dataset_prefix, self.ogs_version)
                     elif k == "proteins_path":