diff --git a/geomagio/processing/update_legacy.py b/geomagio/processing/update_legacy.py
index 4b483cec03acdeb2bc6b2d7b806c6bc59e0230d8..fbe239dde32c3d248ba7d8405985d82098ce3c4d 100644
--- a/geomagio/processing/update_legacy.py
+++ b/geomagio/processing/update_legacy.py
@@ -28,15 +28,14 @@ def update_legacy(
     edge_host: str = os.getenv("EDGE_HOST", "cwbpub.cr.usgs.gov "),
     edge_port: int = os.getenv("EDGE_PORT", 2061),
 ):
-
+    # get specified time interval from time that script is ran
     current_time = datetime.utcnow()
     current_time_string = current_time.strftime("%Y-%m-%d")
     endtime = UTCDateTime(current_time_string) - 1
-
     starttime = endtime - realtime_interval
-
+    # create factory for script outputs
     timeseries_factory = EdgeFactory(host=edge_host, port=edge_port, interval=interval)
-
+    # request data across time interval
     output_timeseries = timeseries_factory.get_timeseries(
         observatory=observatory,
         starttime=starttime,
@@ -44,16 +43,16 @@ def update_legacy(
         channels=channels,
         type="variation",
     )
-
+    # find gaps in legacy data
     output_gaps = get_merged_gaps(get_stream_gaps(output_timeseries))
-
+    # exit script if legacy data is complete
     if len(output_gaps) == 0:
         return
-
+    # get input/output deltas for timeseries processing
     input_interval = get_previous_interval(interval)
     input_delta = get_delta_from_interval(input_interval)
     output_delta = get_delta_from_interval(interval)
-
+    # configure controller to process gaps
     controller = Controller(
         algorithm=FilterAlgorithm(
             input_sample_period=input_delta, output_sample_period=output_delta
@@ -63,7 +62,7 @@ def update_legacy(
         ),
         outputFactory=timeseries_factory,
     )
-
+    # gather, process, and write data into legacy gaps
     for output_gap in output_gaps:
         controller.run(
             observatory=(observatory,),