Find observed timestamp of BUFR sounding

lib/xmet/bufr.py

@@ -1,3 +1,5 @@
+import datetime
+
 from typing import Self
 
 from awips.dataaccess import DataAccessLayer
@@ -52,6 +54,12 @@ class BUFRSounding(Sounding):
 
         sounding = BUFRSounding()
 
+        dt    = response[0].getDataTime()
+        epoch = dt.getRefTime().time / 1000.0
+
+        sounding.timestamp_observed = datetime.datetime.fromtimestamp(epoch,
+                                                                      datetime.UTC)
+
         for item in response:
             params = item.getParameters()