diff --git a/src/spikegadgets_to_nwb/convert_intervals.py b/src/spikegadgets_to_nwb/convert_intervals.py
index e69de29..441910d 100644
--- a/src/spikegadgets_to_nwb/convert_intervals.py
+++ b/src/spikegadgets_to_nwb/convert_intervals.py
@@ -0,0 +1,28 @@
+import pandas as pd
+from pynwb import NWBFile
+from spikegadgets_to_nwb.convert_rec_header import read_header
+
+
+def add_epochs(nwbfile: NWBFile, file_info: pd.DataFrame, date: int, animal: str):
+    session_info = file_info[(file_info.date == date) & (file_info.animal == animal)]
+    for epoch in set(session_info.epoch):
+        rec_file_list = session_info[
+            (session_info.epoch == epoch) & (session_info.file_extension == ".rec")
+        ]
+        start_time = None
+        end_time = None
+        for rec_path in rec_file_list.full_path:
+            file_start_time = get_file_start_time(rec_path)
+            if start_time is None or file_start_time < start_time:
+                start_time = file_start_time
+            end_time = 0.0
+
+        tag = f"{epoch:02d}_{rec_file_list.tag.iloc[0]}"
+        nwbfile.add_epoch(start_time, end_time, tag)
+    return
+
+
+def get_file_start_time(rec_file: str) -> float:
+    header = read_header(rec_file)
+    gconf = header.find("GlobalConfiguration")
+    return float(gconf.attrib["systemTimeAtCreation"].strip()) / 1000.0
diff --git a/src/spikegadgets_to_nwb/tests/test_convert_intervals.py b/src/spikegadgets_to_nwb/tests/test_convert_intervals.py
index e69de29..5674552 100644
--- a/src/spikegadgets_to_nwb/tests/test_convert_intervals.py
+++ b/src/spikegadgets_to_nwb/tests/test_convert_intervals.py
@@ -0,0 +1,29 @@
+from pathlib import Path
+import os
+
+from spikegadgets_to_nwb.data_scanner import get_file_info
+from spikegadgets_to_nwb.convert_intervals import add_epochs
+from spikegadgets_to_nwb.convert_yaml import initialize_nwb, load_metadata
+from spikegadgets_to_nwb.tests.test_convert_rec_header import default_test_xml_tree
+
+path = os.path.dirname(os.path.abspath(__file__))
+
+
+def test_add_epochs():
+    metadata_path = path + "/test_data/20230622_sample_metadata.yml"
+    metadata, _ = load_metadata(metadata_path, [])
+    nwbfile = initialize_nwb(metadata, default_test_xml_tree())
+    try:
+        # running on github
+        file_info = get_file_info(Path(os.environ.get("DOWNLOAD_DIR")))
+    except (TypeError, FileNotFoundError):
+        # running locally
+        file_info = get_file_info(Path(path))
+    add_epochs(nwbfile, file_info, 20230622, "sample")
+    epochs_df = nwbfile.epochs.to_dataframe()
+
+    assert len(epochs_df) == 2
+    assert list(epochs_df.index) == [0, 1]
+    assert list(epochs_df.tags) == [["01_a1"], ["02_a1"]]
+    assert list(epochs_df.start_time) == [1687474797.888, 1687474821.109]
+    assert list(epochs_df.stop_time) == [0.0, 0.0]