diff --git a/modules/aeolus/datasource.py b/modules/aeolus/datasource.py
index 74c72b7faa53081da49cb6368db52af33d1e3586..b47331ecc23733dfe767fe867eff1c9ab13158f4 100644
--- a/modules/aeolus/datasource.py
+++ b/modules/aeolus/datasource.py
@@ -43,10 +43,12 @@ class Files:
 
         return self.flist[k], self.ftimes[k, 0], k
 
-    def get_file(self, timestamp):
+    def get_file(self, timestamp, window=None):
+        if window is None:
+            window = self.span_seconds
         diff = self.ftimes[:, 0] - timestamp
         midx = np.argmin(np.abs(diff))
-        if np.abs(self.ftimes[midx, 0] - timestamp) < self.span_seconds:
+        if np.abs(self.ftimes[midx, 0] - timestamp) < window:
             return self.flist[midx], self.ftimes[midx, 0], midx
         else:
             return None, None, None
@@ -151,10 +153,12 @@ class AMVFiles:
 
         return self.flist[k], self.ftimes[k, 0], k
 
-    def get_file(self, timestamp):
+    def get_file(self, timestamp, window=None):
+        if window is None:
+            window = self.span_seconds
         diff = self.ftimes[:, 0] - timestamp
         midx = np.argmin(np.abs(diff))
-        if np.abs(self.ftimes[midx, 0] - timestamp) < self.span_seconds:
+        if np.abs(self.ftimes[midx, 0] - timestamp) < window:
             return self.flist[midx], self.ftimes[midx, 0], midx
         else:
             return None, None, None