diff --git a/ext/calendar/jewish.c b/ext/calendar/jewish.c
index f4dc7c35ae57c..8c2e9a1cdb347 100644
--- a/ext/calendar/jewish.c
+++ b/ext/calendar/jewish.c
@@ -85,8 +85,8 @@
  *          3 Kislev    29   30   30         29   30   30 (variable)
  *          4 Tevet     29   29   29         29   29   29
  *          5 Shevat    30   30   30         30   30   30
- *          6 Adar I    29   29   29         30   30   30 (variable)
- *          7 Adar II   --   --   --         29   29   29 (optional)
+ *          6 Adar I    --   --   --         30   30   30 (optional)
+ *          7 Adar II   29   29   29         29   29   29
  *          8 Nisan     30   30   30         30   30   30
  *          9 Iyyar     29   29   29         29   29   29
  *         10 Sivan     30   30   30         30   30   30
@@ -100,8 +100,8 @@
  *     have multiple possible spellings in the Roman character set.  I have
  *     chosen to use the spellings found in the Encyclopedia Judaica.
  *
- *     Adar II, the month added for leap years, is sometimes referred to as
- *     the 13th month, but I have chosen to assign it the number 7 to keep
+ *     Adar I, the month added for leap years, is sometimes referred to as
+ *     the 13th month, but I have chosen to assign it the number 6 to keep
  *     the months in chronological order.  This may not be consistent with
  *     other numbering schemes.
  *
@@ -587,11 +587,11 @@ void SdnToJewish(
 				(*pMonth)--;
 				(*pDay) += 30;
 			} else {
-				*pMonth = 6;
+				*pMonth = 7;
 				*pDay = inputDay - tishri1 + 207;
 				if (*pDay > 0)
 					return;
-				(*pMonth)--;
+				(*pMonth) -= 2;
 				(*pDay) += 30;
 			}
 			if (*pDay > 0)
diff --git a/ext/calendar/tests/bug54254.phpt b/ext/calendar/tests/bug54254.phpt
new file mode 100644
index 0000000000000..df9362320c0a6
--- /dev/null
+++ b/ext/calendar/tests/bug54254.phpt
@@ -0,0 +1,59 @@
+--TEST--
+Bug #54254 (cal_days_in_month incompatible with jdtojewish in non-leap-years)
+--SKIPIF--
+<?php include 'skipif.inc'; ?>
+--FILE--
+<?php
+var_dump(cal_days_in_month(CAL_JEWISH, 1, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 2, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 3, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 4, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 5, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 6, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 7, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 8, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 9, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 10, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 11, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 12, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 13, 5771));
+var_dump(cal_days_in_month(CAL_JEWISH, 1, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 2, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 3, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 4, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 5, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 6, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 7, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 8, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 9, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 10, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 11, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 12, 5772));
+var_dump(cal_days_in_month(CAL_JEWISH, 13, 5772));
+--EXPECT--
+int(30)
+int(30)
+int(30)
+int(29)
+int(30)
+int(30)
+int(29)
+int(30)
+int(29)
+int(30)
+int(29)
+int(30)
+int(29)
+int(30)
+int(29)
+int(30)
+int(29)
+int(30)
+int(0)
+int(29)
+int(30)
+int(29)
+int(30)
+int(29)
+int(30)
+int(29)
diff --git a/ext/calendar/tests/jdmonthname.phpt b/ext/calendar/tests/jdmonthname.phpt
index d05d3c595efca..0a3528cf17efe 100644
--- a/ext/calendar/tests/jdmonthname.phpt
+++ b/ext/calendar/tests/jdmonthname.phpt
@@ -178,7 +178,7 @@ Heshvan
 Kislev
 Tevet
 Shevat
-AdarI
+AdarII
 Nisan
 Iyyar
 Sivan
@@ -279,7 +279,7 @@ Heshvan
 Kislev
 Tevet
 Shevat
-AdarI
+AdarII
 Nisan
 Iyyar
 Sivan
diff --git a/ext/calendar/tests/jdtojewish.phpt b/ext/calendar/tests/jdtojewish.phpt
index 484b95749cca9..a88be45475a6e 100644
--- a/ext/calendar/tests/jdtojewish.phpt
+++ b/ext/calendar/tests/jdtojewish.phpt
@@ -14,10 +14,11 @@ var_dump(jdtojewish(gregoriantojd(10,28,2002))."\r\n".
 	jdtojewish(gregoriantojd(10,8,2002),true, CAL_JEWISH_ADD_GERESHAYIM)."\r\n".
 	jdtojewish(gregoriantojd(10,8,2002),true, CAL_JEWISH_ADD_GERESHAYIM+CAL_JEWISH_ADD_ALAFIM_GERESH)."\r\n".
 	jdtojewish(gregoriantojd(10,8,2002),true, CAL_JEWISH_ADD_GERESHAYIM+CAL_JEWISH_ADD_ALAFIM)."\r\n".
-	jdtojewish(gregoriantojd(10,8,2002),true, CAL_JEWISH_ADD_GERESHAYIM+CAL_JEWISH_ADD_ALAFIM+CAL_JEWISH_ADD_ALAFIM_GERESH)."\r\n");
+	jdtojewish(gregoriantojd(10,8,2002),true, CAL_JEWISH_ADD_GERESHAYIM+CAL_JEWISH_ADD_ALAFIM+CAL_JEWISH_ADD_ALAFIM_GERESH)."\r\n".
+	jdtojewish(gregoriantojd(3,10,2007))."\r\n");
 ?>
 --EXPECT--
-string(184) "2/22/5763
+string(195) "2/22/5763
 כב חשון התשסג
 כב חשון ה'תשסג
 כב חשון ה אלפים תשסג
@@ -27,4 +28,5 @@ string(184) "2/22/5763
 ב' חשון ה'תשס"ג
 ב' חשון ה אלפים תשס"ג
 ב' חשון ה' אלפים תשס"ג
+7/20/5767
 "