diff --git a/src/xfel_calibrate/calibrate.py b/src/xfel_calibrate/calibrate.py
index 5cd5c747f4d81ed7890dc4d77a25f9c5d0b82f2d..fa14605bf1068aa43b0e512332b607ed0afb0b74 100755
--- a/src/xfel_calibrate/calibrate.py
+++ b/src/xfel_calibrate/calibrate.py
@@ -610,7 +610,7 @@ def run(argv=None):
 
     # request_time is in local timezone
     if args["request_time"] == "Now":
-        request_time = datetime.now()
+        request_time = datetime.now(tz=timezone.utc)
     else:
         request_time = datetime.fromisoformat(args["request_time"])