diff --git a/UPGRADING b/UPGRADING
index 1bc576d007ce6..a9306231eaf87 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -303,6 +303,10 @@ PHP 8.3 UPGRADE NOTES
     significant digits before the decimal point. Previously negative $decimals
     got silently ignored and the number got rounded to zero decimal places.
 
+- Calendar
+  . easter_date() now supports years from 1970 to 2,000,000,000 on 64-bit systems,
+    previously it only supported years in the range from 1970 to 2037.
+
 ========================================
 6. New Functions
 ========================================
diff --git a/ext/calendar/easter.c b/ext/calendar/easter.c
index c319abd17fef0..579e8af72eac2 100644
--- a/ext/calendar/easter.c
+++ b/ext/calendar/easter.c
@@ -13,6 +13,7 @@
    | Authors: Shane Caraveo             <shane@caraveo.com>               |
    |          Colin Viebrock            <colin@easydns.com>               |
    |          Hartmut Holzgraefe        <hholzgra@php.net>                |
+   |          Arne Perschke             <a.perschke@hctec.net>            |
    +----------------------------------------------------------------------+
  */
 
@@ -21,6 +22,10 @@
 #include "sdncal.h"
 #include <time.h>
 
+/**
+ * If `gm` is true this will return the timestamp at midnight on Easter of the given year. If it is false this
+ * will return the number of days Easter is after March 21st.
+ */
 static void _cal_easter(INTERNAL_FUNCTION_PARAMETERS, bool gm)
 {
 	/* based on code by Simon Kershaw, <webmaster@ely.anglican.org> */
@@ -48,10 +53,27 @@ static void _cal_easter(INTERNAL_FUNCTION_PARAMETERS, bool gm)
 		}
 	}
 
-	if (gm && (year<1970 || year>2037)) {				/* out of range for timestamps */
+	#ifdef ZEND_ENABLE_ZVAL_LONG64
+	/* Compiling for 64bit, allow years between 1970 and 2.000.000.000 */	
+	if (gm && year < 1970) {
+		/* timestamps only start after 1970 */
+		zend_argument_value_error(1, "must be a year after 1970 (inclusive)");
+		RETURN_THROWS();
+	}
+
+	if (gm && year > 2000000000) {
+		/* timestamps only go up to the year 2.000.000.000 */
+		zend_argument_value_error(1, "must be a year before 2.000.000.000 (inclusive)");
+		RETURN_THROWS();
+	}
+	#else
+	/* Compiling for 32bit, allow years between 1970 and 2037 */	
+	if (gm && (year < 1970 || year > 2037)) {
 		zend_argument_value_error(1, "must be between 1970 and 2037 (inclusive)");
 		RETURN_THROWS();
 	}
+	#endif
+
 
 	golden = (year % 19) + 1;					/* the Golden number */
 
diff --git a/ext/calendar/tests/easter_date.phpt b/ext/calendar/tests/easter_date_32bit.phpt
similarity index 81%
rename from ext/calendar/tests/easter_date.phpt
rename to ext/calendar/tests/easter_date_32bit.phpt
index a41c310de9b89..52f880edc1131 100644
--- a/ext/calendar/tests/easter_date.phpt
+++ b/ext/calendar/tests/easter_date_32bit.phpt
@@ -1,5 +1,7 @@
 --TEST--
-easter_date()
+Test easter_date() on 32bit systems
+--SKIPIF--
+<?php if (PHP_INT_SIZE != 4) die("skip 32-bit only"); ?>
 --INI--
 date.timezone=UTC
 --ENV--
diff --git a/ext/calendar/tests/easter_date_64bit.phpt b/ext/calendar/tests/easter_date_64bit.phpt
new file mode 100644
index 0000000000000..3939b7e4a4d41
--- /dev/null
+++ b/ext/calendar/tests/easter_date_64bit.phpt
@@ -0,0 +1,33 @@
+--TEST--
+Test easter_date() on 64bit systems
+--SKIPIF--
+<?php if (PHP_INT_SIZE != 8) die("skip 64-bit only"); ?>
+--INI--
+date.timezone=UTC
+--ENV--
+TZ=UTC
+--EXTENSIONS--
+calendar
+--FILE--
+<?php
+putenv('TZ=UTC');
+echo date("Y-m-d", easter_date(2000))."\n";
+echo date("Y-m-d", easter_date(2001))."\n";
+echo date("Y-m-d", easter_date(2002))."\n";
+echo date("Y-m-d", easter_date(2045))."\n";
+echo date("Y-m-d", easter_date(2046))."\n";
+echo date("Y-m-d", easter_date(2047))."\n";
+try {
+    easter_date(1492);
+} catch (ValueError $ex) {
+    echo "{$ex->getMessage()}\n";
+}
+?>
+--EXPECT--
+2000-04-23
+2001-04-15
+2002-03-31
+2045-04-09
+2046-03-25
+2047-04-14
+easter_date(): Argument #1 ($year) must be a year after 1970 (inclusive)
diff --git a/ext/calendar/tests/easter_date_checks_upper_bound_32bit.phpt b/ext/calendar/tests/easter_date_checks_upper_bound_32bit.phpt
new file mode 100644
index 0000000000000..6a9cee8027fb7
--- /dev/null
+++ b/ext/calendar/tests/easter_date_checks_upper_bound_32bit.phpt
@@ -0,0 +1,21 @@
+--TEST--
+Test easter_date() on 32bit systems checks the upper year limit
+--SKIPIF--
+<?php if (PHP_INT_SIZE != 4) die("skip 32-bit only"); ?>
+--INI--
+date.timezone=UTC
+--ENV--
+TZ=UTC
+--EXTENSIONS--
+calendar
+--FILE--
+<?php
+putenv('TZ=UTC');
+try {
+    easter_date(2040);
+} catch (ValueError $ex) {
+    echo "{$ex->getMessage()}\n";
+}
+?>
+--EXPECT--
+easter_date(): Argument #1 ($year) must be between 1970 and 2037 (inclusive)
diff --git a/ext/calendar/tests/easter_date_checks_upper_bound_64bit.phpt b/ext/calendar/tests/easter_date_checks_upper_bound_64bit.phpt
new file mode 100644
index 0000000000000..2c7afbdfa2d97
--- /dev/null
+++ b/ext/calendar/tests/easter_date_checks_upper_bound_64bit.phpt
@@ -0,0 +1,21 @@
+--TEST--
+Test easter_date() on 64bit systems checks the upper year limit
+--SKIPIF--
+<?php if (PHP_INT_SIZE != 8) die("skip 64-bit only"); ?>
+--INI--
+date.timezone=UTC
+--ENV--
+TZ=UTC
+--EXTENSIONS--
+calendar
+--FILE--
+<?php
+putenv('TZ=UTC');
+try {
+    easter_date(293274701009);
+} catch (ValueError $ex) {
+    echo "{$ex->getMessage()}\n";
+}
+?>
+--EXPECT--
+easter_date(): Argument #1 ($year) must be a year before 2.000.000.000 (inclusive)