diff --git a/src/regex.ts b/src/regex.ts
index f81088e..73441cd 100644
--- a/src/regex.ts
+++ b/src/regex.ts
@@ -359,7 +359,7 @@ export const edtfEventTextMatchIndex = ++edtfIndex;
  *
  */
 export const BCE_START_REGEX = new RegExp(
-  `^\\s*(\\d{1,5})\\s?(BCE|BC|AD|CE)?(?:\\s?[–-]\\s?(\\d{1,5})\\s?(BCE|BC|AD|CE)?)?(?=\\s*:)(.*)`,
+  `^\\s*(\\d{1,7})\\s?(BCE|BC|AD|CE)?(?:\\s?[–-]\\s?(\\d{1,7})\\s?(BCE|BC|AD|CE)?)?(?=\\s*:)(.*)`,
   "i"
 );
 let BCEIndex = -1;