diff --git a/README.md b/README.md
index 01b6b32..eea258a 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,7 @@ N_GSPS: The number of gsps you want to pull
 INCLUDE_NATIONAL: Option to load national data, or not
 UK_LONDON_HOUR: Optional to check UK London hour. This means can run this service at the same
    UTC times, independently of the clock change.
+BACKFILL_HOURS: Optional, defaults to 2. The amount of hours of data that is backfilled.
 
 These options can also be enter like this:
 ```
diff --git a/gspconsumer/app.py b/gspconsumer/app.py
index c9c0c07..e2ca202 100644
--- a/gspconsumer/app.py
+++ b/gspconsumer/app.py
@@ -145,7 +145,8 @@ def pull_data_and_save(
         datetime_utc = datetime.utcnow().replace(tzinfo=timezone.utc)  # add timezone
 
     if regime == "in-day":
-        start = datetime_utc - timedelta(hours=1)
+        backfill_hours = os.getenv("BACKFILL_HOURS", 2)
+        start = datetime_utc - timedelta(hours=backfill_hours)
         end = datetime_utc + timedelta(minutes=30)
     else:
         start = datetime_utc.replace(hour=0, minute=0, second=0, microsecond=0) - timedelta(