diff --git a/ext/date/date_core.c b/ext/date/date_core.c
index d1605bb..09bf0c7 100644
--- a/ext/date/date_core.c
+++ b/ext/date/date_core.c
@@ -248,6 +248,11 @@ f_negative_p(VALUE x)
 #define date_sg_t double
 #endif
 
+#define JULIAN_EPOCH_DATE "-4712-01-01"
+#define JULIAN_EPOCH_DATETIME JULIAN_EPOCH_DATE "T00:00:00+00:00"
+#define JULIAN_EPOCH_DATETIME_RFC3339 "Mon, 1 Jan -4712 00:00:00 +0000"
+#define JULIAN_EPOCH_DATETIME_HTTPDATE "Mon, 01 Jan -4712 00:00:00 GMT"
+
 /* A set of nth, jd, df and sf denote ajd + 1/2.  Each ajd begin at
  * noon of GMT (assume equal to UTC).  However, this begins at
  * midnight.
@@ -4425,7 +4430,7 @@ date_s_strptime(int argc, VALUE *argv, VALUE klass)
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01");
+	str = rb_str_new2(JULIAN_EPOCH_DATE);
       case 1:
 	fmt = rb_str_new2("%F");
       case 2:
@@ -4478,8 +4483,7 @@ date_s__parse_internal(int argc, VALUE *argv, VALUE klass)
 {
     VALUE vstr, vcomp, hash, opt;
 
-    rb_scan_args(argc, argv, "11:", &vstr, &vcomp, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "11:", &vstr, &vcomp, &opt);
     check_limit(vstr, opt);
     StringValue(vstr);
     if (!rb_enc_str_asciicompat_p(vstr))
@@ -4566,12 +4570,11 @@ date_s_parse(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, comp, sg, opt;
 
-    rb_scan_args(argc, argv, "03:", &str, &comp, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "03:", &str, &comp, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01");
+	str = rb_str_new2(JULIAN_EPOCH_DATE);
       case 1:
 	comp = Qtrue;
       case 2:
@@ -4646,12 +4649,11 @@ date_s_iso8601(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01");
+	str = rb_str_new2(JULIAN_EPOCH_DATE);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -4717,12 +4719,11 @@ date_s_rfc3339(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -4786,12 +4787,11 @@ date_s_xmlschema(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01");
+	str = rb_str_new2(JULIAN_EPOCH_DATE);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -4857,11 +4857,11 @@ date_s_rfc2822(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("Mon, 1 Jan -4712 00:00:00 +0000");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME_RFC3339);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -4925,11 +4925,11 @@ date_s_httpdate(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("Mon, 01 Jan -4712 00:00:00 GMT");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME_HTTPDATE);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -4997,12 +4997,11 @@ date_s_jisx0301(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01");
+	str = rb_str_new2(JULIAN_EPOCH_DATE);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -8375,7 +8374,7 @@ datetime_s_strptime(int argc, VALUE *argv, VALUE klass)
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME);
       case 1:
 	fmt = rb_str_new2("%FT%T%z");
       case 2:
@@ -8423,12 +8422,11 @@ datetime_s_parse(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, comp, sg, opt;
 
-    rb_scan_args(argc, argv, "03:", &str, &comp, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "03:", &str, &comp, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME);
       case 1:
 	comp = Qtrue;
       case 2:
@@ -8470,12 +8468,11 @@ datetime_s_iso8601(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -8510,12 +8507,11 @@ datetime_s_rfc3339(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -8550,12 +8546,11 @@ datetime_s_xmlschema(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -8591,12 +8586,11 @@ datetime_s_rfc2822(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("Mon, 1 Jan -4712 00:00:00 +0000");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME_RFC3339);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -8631,12 +8625,11 @@ datetime_s_httpdate(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("Mon, 01 Jan -4712 00:00:00 GMT");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME_HTTPDATE);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
@@ -8676,12 +8669,11 @@ datetime_s_jisx0301(int argc, VALUE *argv, VALUE klass)
 {
     VALUE str, sg, opt;
 
-    rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
-    if (!NIL_P(opt)) argc--;
+    argc = rb_scan_args(argc, argv, "02:", &str, &sg, &opt);
 
     switch (argc) {
       case 0:
-	str = rb_str_new2("-4712-01-01T00:00:00+00:00");
+	str = rb_str_new2(JULIAN_EPOCH_DATETIME);
       case 1:
 	sg = INT2FIX(DEFAULT_SG);
     }
diff --git a/test/date/test_date_strftime.rb b/test/date/test_date_strftime.rb
index 976e48f..6ad69c0 100644
--- a/test/date/test_date_strftime.rb
+++ b/test/date/test_date_strftime.rb
@@ -416,9 +416,10 @@ def test__different_format
     assert_equal(d2, DateTime.rfc3339('2001-02-03T04:05:06.123456+00:00', limit: 64))
     assert_equal(d2, DateTime.jisx0301('H13.02.03T04:05:06.123456+00:00', limit: 64))
 
-    assert_raise(ArgumentError) { DateTime.iso8601('2001-02-03T04:05:06.123456+00:00', limit: 1) }
-    assert_raise(ArgumentError) { DateTime.rfc3339('2001-02-03T04:05:06.123456+00:00', limit: 1) }
-    assert_raise(ArgumentError) { DateTime.jisx0301('H13.02.03T04:05:06.123456+00:00', limit: 1) }
+    exceeds = /string length \(\d+\) exceeds/
+    assert_raise_with_message(ArgumentError, exceeds) {DateTime.iso8601('2001-02-03T04:05:06.123456+00:00', limit: 1)}
+    assert_raise_with_message(ArgumentError, exceeds) {DateTime.rfc3339('2001-02-03T04:05:06.123456+00:00', limit: 1)}
+    assert_raise_with_message(ArgumentError, exceeds) {DateTime.jisx0301('H13.02.03T04:05:06.123456+00:00', limit: 1)}
 
     %w(M06.01.01
        M45.07.29