diff --git a/freqtrade/freqai/data_kitchen.py b/freqtrade/freqai/data_kitchen.py
index 80c037a3d..5ca64e504 100644
--- a/freqtrade/freqai/data_kitchen.py
+++ b/freqtrade/freqai/data_kitchen.py
@@ -909,10 +909,10 @@ class FreqaiDataKitchen:
         coin, _ = pair.split("/")
         self.data_path = Path(
             self.full_path
-            / str("sub-train" + "-" + pair.split("/")[0] + "_" + str(int(trained_timerange.stopts)))
+            / f"sub-train-{pair.split('/')[0]}_{int(trained_timerange.stopts)}"
         )
 
-        self.model_filename = "cb_" + coin.lower() + "_" + str(int(trained_timerange.stopts))
+        self.model_filename = f"cb_{coin.lower()}_{int(trained_timerange.stopts)}"
 
     def download_all_data_for_training(self, timerange: TimeRange) -> None:
         """
diff --git a/freqtrade/freqai/freqai_interface.py b/freqtrade/freqai/freqai_interface.py
index c393420b5..a8527f9e1 100644
--- a/freqtrade/freqai/freqai_interface.py
+++ b/freqtrade/freqai/freqai_interface.py
@@ -210,11 +210,12 @@ class IFreqaiModel(ABC):
                 )
             )
             if not self.model_exists(
-                metadata["pair"], dk, trained_timestamp=trained_timestamp.stopts
+                metadata["pair"], dk, trained_timestamp=int(trained_timestamp.stopts)
             ):
                 dk.find_features(dataframe_train)
                 self.model = self.train(dataframe_train, metadata["pair"], dk)
-                self.dd.pair_dict[metadata["pair"]]["trained_timestamp"] = trained_timestamp.stopts
+                self.dd.pair_dict[metadata["pair"]]["trained_timestamp"] = int(
+                    trained_timestamp.stopts)
                 dk.set_new_model_names(metadata["pair"], trained_timestamp)
                 dk.save_data(self.model, metadata["pair"])
             else:
diff --git a/tests/freqai/test_freqai_interface.py b/tests/freqai/test_freqai_interface.py
index 6699ef563..e4df8772c 100644
--- a/tests/freqai/test_freqai_interface.py
+++ b/tests/freqai/test_freqai_interface.py
@@ -90,7 +90,7 @@ def test_start_backtesting(mocker, freqai_conf):
 
     df = freqai.dk.use_strategy_to_populate_indicators(strategy, corr_df, base_df, "LTC/BTC")
 
-    metadata = {"pair": "ADA/BTC"}
+    metadata = {"pair": "LTC/BTC"}
     freqai.start_backtesting(df, metadata, freqai.dk)
     model_folders = [x for x in freqai.dd.full_path.iterdir() if x.is_dir()]
 
@@ -99,6 +99,32 @@ def test_start_backtesting(mocker, freqai_conf):
     shutil.rmtree(Path(freqai.dk.full_path))
 
 
+def test_start_backtesting_subdaily_backtest_period(mocker, freqai_conf):
+    freqai_conf.update({"timerange": "20180120-20180124"})
+    freqai_conf.get("freqai", {}).update({"backtest_period_days": 0.5})
+    strategy = get_patched_freqai_strategy(mocker, freqai_conf)
+    exchange = get_patched_exchange(mocker, freqai_conf)
+    strategy.dp = DataProvider(freqai_conf, exchange)
+    strategy.freqai_info = freqai_conf.get("freqai", {})
+    freqai = strategy.freqai
+    freqai.live = False
+    freqai.dk = FreqaiDataKitchen(freqai_conf, freqai.dd)
+    timerange = TimeRange.parse_timerange("20180110-20180130")
+    freqai.dk.load_all_pair_histories(timerange)
+    sub_timerange = TimeRange.parse_timerange("20180110-20180130")
+    corr_df, base_df = freqai.dk.get_base_and_corr_dataframes(sub_timerange, "LTC/BTC")
+
+    df = freqai.dk.use_strategy_to_populate_indicators(strategy, corr_df, base_df, "LTC/BTC")
+
+    metadata = {"pair": "LTC/BTC"}
+    freqai.start_backtesting(df, metadata, freqai.dk)
+    model_folders = [x for x in freqai.dd.full_path.iterdir() if x.is_dir()]
+    pytest.set_trace()
+    assert len(model_folders) == 8
+
+    shutil.rmtree(Path(freqai.dk.full_path))
+
+
 def test_start_backtesting_from_existing_folder(mocker, freqai_conf, caplog):
     freqai_conf.update({"timerange": "20180120-20180130"})
     strategy = get_patched_freqai_strategy(mocker, freqai_conf)