diff --git a/src/OpenSearch.Client/Aggregations/AggregateFormatter.cs b/src/OpenSearch.Client/Aggregations/AggregateFormatter.cs
index 9216b29a56..59674986e7 100644
--- a/src/OpenSearch.Client/Aggregations/AggregateFormatter.cs
+++ b/src/OpenSearch.Client/Aggregations/AggregateFormatter.cs
@@ -843,7 +843,7 @@ private IBucket GetDateHistogramBucket(ref JsonReader reader, IJsonFormatterReso
 			reader.ReadNext(); // ,
 			reader.ReadNext(); // "key"
 			reader.ReadNext(); // :
-			var key = reader.ReadInt64();
+			var key = reader.ReadDouble();
 			reader.ReadNext(); // ,
 			reader.ReadNext(); // "doc_count"
 			reader.ReadNext(); // :