diff --git a/packages/core/src/Timestamp/formatInstant.ts b/packages/core/src/Timestamp/formatInstant.ts
index f0ba7df3222..1a40316e614 100644
--- a/packages/core/src/Timestamp/formatInstant.ts
+++ b/packages/core/src/Timestamp/formatInstant.ts
@@ -182,28 +182,24 @@ export function formatInstant(
         ...FULL_OPTIONS,
         timeZoneName: timeZoneNameStyle,
         ...zone,
-        calendar: 'gregory',
       }).format(date);
 
     case 'date':
       return new Intl.DateTimeFormat(locale, {
         ...SHARED_DATE_FORMAT_OPTIONS.date,
         ...zone,
-        calendar: 'gregory',
       }).format(date);
 
     case 'date_long':
       return new Intl.DateTimeFormat(locale, {
         ...SHARED_DATE_FORMAT_OPTIONS.date_long,
         ...zone,
-        calendar: 'gregory',
       }).format(date);
 
     case 'date_weekday':
       return new Intl.DateTimeFormat(locale, {
         ...SHARED_DATE_FORMAT_OPTIONS.date_weekday,
         ...zone,
-        calendar: 'gregory',
       }).format(date);
 
     case 'date_time':
@@ -211,7 +207,6 @@ export function formatInstant(
         ...DATE_TIME_OPTIONS,
         ...zoneName,
         ...zone,
-        calendar: 'gregory',
       }).format(date);
 
     case 'time':