Converters: handle ValueError when year for duration is out of range

`datetime` objects only support a year up to 9999.

Fixes #906

1 files changed, 4 insertions, 1 deletions

diff --git a/bot/converters.py b/bot/converters.py
index 72c46fdf0..4deb59f87 100644
--- a/bot/converters.py
+++ b/bot/converters.py
@@ -217,7 +217,10 @@ class Duration(Converter):
         delta = relativedelta(**duration_dict)
         now = datetime.utcnow()
 
-        return now + delta
+        try:
+            return now + delta
+        except ValueError:
+            raise BadArgument(f"`{duration}` results in a datetime outside the supported range.")
 
 
 class ISODateTime(Converter):