diff --git a/tests/test_eumetsat.py b/tests/test_eumetsat.py
index cb0cb8b4..a1a75b78 100644
--- a/tests/test_eumetsat.py
+++ b/tests/test_eumetsat.py
@@ -1,4 +1,25 @@
 """Tests for satip.eumetsat."""
+import glob
+import os
+from pathlib import Path
+
+import pandas as pd
+import xarray as xr
+
+from satip import eumetsat
+from satip.eumetsat import eumetsat_cloud_name_to_datetime, eumetsat_filename_to_datetime
+from satip.utils import (
+    check_if_timestep_exists,
+    load_cloudmask_to_dataset,
+    load_native_to_dataset,
+    save_dataset_to_zarr,
+)
+
+RSS_ID = "EO:EUM:DAT:MSG:MSG15-RSS"
+CLOUD_ID = "EO:EUM:DAT:MSG:RSS-CLM"
+
+user_key = os.environ.get("EUMETSAT_USER_KEY")
+user_secret = os.environ.get("EUMETSAT_USER_SECRET")
 
 
 def test_filename_to_datetime():
@@ -9,3 +30,86 @@ def test_filename_to_datetime():
 def test_data_tailor():
     """If there were a test here, there would also be a docstring here."""
     pass
+
+
+def test_datetime_check_native():
+    """ "Check that checking datetime works"""
+    RSS_ID = "EO:EUM:DAT:MSG:MSG15-RSS"
+    CLOUD_ID = "EO:EUM:DAT:MSG:RSS-CLM"
+
+    user_key = os.environ.get("EUMETSAT_USER_KEY")
+    user_secret = os.environ.get("EUMETSAT_USER_SECRET")
+    download_manager = eumetsat.DownloadManager(
+        user_key=user_key,
+        user_secret=user_secret,
+        data_dir=os.getcwd(),
+        log_fp=os.path.join(os.getcwd(), "log.txt"),
+        logger_name="Plotting_test",
+    )
+    download_manager.download_date_range(
+        start_date="2020-06-01 11:59:00", end_date="2020-06-01 12:00:00", product_id=RSS_ID
+    )
+    rss_filename = list(glob.glob(os.path.join(os.getcwd(), "*.nat")))
+    rss_dataset, hrv_dataset = load_native_to_dataset(
+        Path(rss_filename[0]), temp_directory=Path(os.getcwd()), area="UK"
+    )
+
+    # Save to Zarrs, to then load them back
+    save_dataset_to_zarr(
+        rss_dataset,
+        zarr_path=os.path.join(os.getcwd(), "rss.zarr"),
+        channel_chunk_size=11,
+        dtype="int16",
+        zarr_mode="w",
+    )
+    save_dataset_to_zarr(
+        hrv_dataset,
+        zarr_path=os.path.join(os.getcwd(), "hrv.zarr"),
+        channel_chunk_size=1,
+        dtype="int16",
+        zarr_mode="w",
+    )
+
+    zarr_dataset = xr.open_zarr(os.path.join(os.getcwd(), "rss.zarr"), consolidated=True)
+    base_filename = Path(rss_filename[0]).name
+    file_timestep = eumetsat_filename_to_datetime(str(base_filename))
+    assert check_if_timestep_exists(pd.Timestamp(file_timestep).round("5 min"), zarr_dataset)
+    zarr_dataset = xr.open_zarr(os.path.join(os.getcwd(), "hrv.zarr"), consolidated=True)
+    assert check_if_timestep_exists(pd.Timestamp(file_timestep).round("5 min"), zarr_dataset)
+
+
+def test_datetime_check_cloud_mask():
+    """ "Check that checking datetime works"""
+    RSS_ID = "EO:EUM:DAT:MSG:MSG15-RSS"
+    CLOUD_ID = "EO:EUM:DAT:MSG:RSS-CLM"
+
+    user_key = os.environ.get("EUMETSAT_USER_KEY")
+    user_secret = os.environ.get("EUMETSAT_USER_SECRET")
+    download_manager = eumetsat.DownloadManager(
+        user_key=user_key,
+        user_secret=user_secret,
+        data_dir=os.getcwd(),
+        log_fp=os.path.join(os.getcwd(), "log.txt"),
+        logger_name="Plotting_test",
+    )
+    download_manager.download_date_range(
+        start_date="2020-06-01 11:59:00", end_date="2020-06-01 12:00:00", product_id=CLOUD_ID
+    )
+    cloud_mask_filename = list(glob.glob(os.path.join(os.getcwd(), "*.grb")))
+    cloudmask_dataset = load_cloudmask_to_dataset(
+        Path(cloud_mask_filename[0]), temp_directory=Path(os.getcwd()), area="UK"
+    )
+
+    # Save to Zarrs, to then load them back
+    save_dataset_to_zarr(
+        cloudmask_dataset,
+        zarr_path=os.path.join(os.getcwd(), "cloud.zarr"),
+        channel_chunk_size=1,
+        dtype="int8",
+        zarr_mode="w",
+    )
+
+    zarr_dataset = xr.open_zarr(os.path.join(os.getcwd(), "cloud.zarr"), consolidated=True)
+    base_filename = Path(cloud_mask_filename[0]).name
+    file_timestep = eumetsat_cloud_name_to_datetime(str(base_filename))
+    assert check_if_timestep_exists(pd.Timestamp(file_timestep).round("5 min"), zarr_dataset)