diff --git a/core/src/components/datetime/datetime.tsx b/core/src/components/datetime/datetime.tsx
index ced53c64bb..82efb51321 100644
--- a/core/src/components/datetime/datetime.tsx
+++ b/core/src/components/datetime/datetime.tsx
@@ -353,7 +353,7 @@ export class Datetime implements ComponentInterface {
           this.activePartsClone = [...valueDateParts];
         } else {
           const { month, day, year, hour, minute } = valueDateParts;
-          const ampm = hour ? (hour >= 12 ? 'pm' : 'am') : undefined;
+          const ampm = hour != null ? (hour >= 12 ? 'pm' : 'am') : undefined;
 
           this.activePartsClone = {
             ...this.activeParts,