diff --git a/config.yml b/config.yml
index ebb0a57..bc57036 100644
--- a/config.yml
+++ b/config.yml
@@ -52,6 +52,8 @@ amda: "http://amda.irap.omp.eu/DDService/getDataUrl.php?dataSet={dataSet}&StartT
 
 defaults:
   input_slug: 'om'
+  relative_before: 1
+  relative_after: 1
 
 # Data files are in data/catalog/
 # Constraints are joined by an outer OR and an inner AND
diff --git a/web/hp_cmd.py b/web/hp_cmd.py
index be038d0..88ce106 100644
--- a/web/hp_cmd.py
+++ b/web/hp_cmd.py
@@ -1,6 +1,6 @@
 import sys
 
-from run import generate_csv_file_if_needed, init_console_logger, config
+from run import generate_csv_file_if_needed, init_console_logger, config, get_default_sta_sto
 from datetime import datetime
 import argparse
 
@@ -27,9 +27,9 @@ if __name__ == "__main__":
         _logger = init_console_logger()
 
     if args.hpcmd_name == 'csv_gen':
-        # todo: build default dates in not -b or -e
-        start_date = datetime.strptime(args.begin, '%Y%m%d')
-        stop_date = datetime.strptime(args.end, '%Y%m%d')
+        # build default dates in not -b or not -e
+        sta, sto = get_default_sta_sto( args.begin, args.end)
+
         if args.all:
             # build the {target_slug: [input list]} dictionnary from config.yaml
             targets = {t['slug']: list(t['models'].keys()) for t in config['targets']}
@@ -43,4 +43,4 @@ if __name__ == "__main__":
                 print(f"generating csv for {_t}/ {_i}")
                 if args.dry_run:
                     continue
-                generate_csv_file_if_needed(_t, _i, start_date, stop_date)
+                generate_csv_file_if_needed(_t, _i, sta, sto)
diff --git a/web/run.py b/web/run.py
index 61a5167..6092549 100755
--- a/web/run.py
+++ b/web/run.py
@@ -1082,26 +1082,51 @@ def get_input_slug_from_query(inp=None):
     return input_slug
 
 
-def get_interval_from_query():
+def get_default_sta_sto(sta=None, sto=None):
+
+    # TODO : maybe get from configuration
+    relative_after = config['defaults']['relative_after']
+    relative_before = config['defaults']['relative_before']
+    before = relativedelta(months=relative_before)
+    after = relativedelta(months=relative_after)
+
+    if sta is None and sto is None:
+        today = datetime.datetime.now().replace(hour=0, minute=0, second=0)
+        sta_date = today - before
+        sto_date = today + after
+
+    if sta is None and sto is not None:
+        sto_date = dateparser.isoparse(sto)
+        sta_date = sto_date - before
+
+    if sta is not None and sto is None:
+        sta_date = dateparser.isoparse(sta)
+        sto_date = sta_date + after
+
+    return sta_date, sto_date
+
+
+def get_interval_from_query(_req=None):
     """
-    Get the interval from the query, or from defaults.
+    Get the interval from the query as flask.request, or from defaults.
     Returns ISO date strings.
     """
-    before = relativedelta(months=1)
-    after = relativedelta(months=1)
-    today = datetime.datetime.now().replace(hour=0, minute=0, second=0)
-    started_at = today - before
-    stopped_at = today + after
-    default_started_at = started_at.strftime(FILE_DATE_FMT)
-    default_stopped_at = stopped_at.strftime(FILE_DATE_FMT)
-
-    started_at = request.args.get('started_at', default_started_at)
-    stopped_at = request.args.get('stopped_at', default_stopped_at)
-
-    d_started_at = dateparser.isoparse(started_at)
-    d_stopped_at = dateparser.isoparse(stopped_at)
-    started_at = d_started_at.strftime(FILE_DATE_FMT)
-    stopped_at = d_stopped_at.strftime(FILE_DATE_FMT)
+
+    sta_default, sto_default  = get_default_sta_sto()
+
+    # convert to string
+    started_at_default = sta_default.strftime(FILE_DATE_FMT)
+    stopped_at_default = sto_default.strftime(FILE_DATE_FMT)
+
+    if _req is not None and 'Request' == _req.__class__.__name__:
+        started_at_str = _req.args.get('started_at', started_at_default)
+        stopped_at_str = _req.args.get('stopped_at', stopped_at_default)
+
+    # convert back to proper format
+    started_at_date = dateparser.isoparse(started_at_str)
+    stopped_at_date = dateparser.isoparse(stopped_at_str)
+    started_at = started_at_date.strftime(FILE_DATE_FMT)
+    stopped_at = stopped_at_date.strftime(FILE_DATE_FMT)
 
     return started_at, stopped_at
 
@@ -1266,7 +1291,7 @@ def home():
     parameters = sorted(parameters, key=lambda x: x['position'])
     input_slug = get_input_slug_from_query()
     targets = [t for t in config['targets'] if not t['locked']]
-    started_at, stopped_at = get_interval_from_query()
+    started_at, stopped_at = get_interval_from_query(request)
     for i, target in enumerate(targets):
         targets[i]['catalog_layers'] = get_catalog_layers(
             input_slug, target['slug'], started_at, stopped_at
@@ -1771,7 +1796,7 @@ def cache_warmup():
     Warms up the cache for the current day.
     """
     warmup_started_at = datetime.datetime.now()
-    sta, sto = get_interval_from_query()
+    sta, sto = get_interval_from_query(request)
     inp = config['defaults']['input_slug']  # default input, maybe warm them all up ?
 
     targets = get_active_targets()
--
libgit2 0.21.2