diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index 1031bd9..11605ab 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -1574,3 +1574,64 @@
 X509 Get time (UTC invalid sec)
 depends_on:MBEDTLS_X509_USE_C
 x509_get_time:MBEDTLS_ASN1_UTC_TIME:"001130235960Z":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (UTC without time zone)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"000229121212":0:2000:2:29:12:12:12
+
+X509 Get time (UTC with invalid time zone #1)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"000229121212J":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (UTC with invalid time zone #2)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"000229121212+0300":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (Date with invalid tag)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_CONTEXT_SPECIFIC:"000229121212":MBEDTLS_ERR_X509_INVALID_DATE+MBEDTLS_ERR_ASN1_UNEXPECTED_TAG:0:0:0:0:0:0
+
+X509 Get time (UTC, truncated)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"000229121":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (Generalized Time, truncated)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_GENERALIZED_TIME:"20000229121":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (UTC without seconds)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"0002291212":MBEDTLS_ERR_X509_INVALID_DATE:2000:2:29:12:12:0
+
+X509 Get time (UTC without seconds and with invalid time zone #1)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"0002291212J":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (UTC without second and with invalid time zone #2)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"0002291212+0300":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (UTC invalid character in year)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"0\1130231212Z":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (UTC invalid character in month)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"001%30231212Z":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (UTC invalid character in day)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"0011`0231212Z":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (UTC invalid character in hour)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"0011302h1212Z":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (UTC invalid character in min)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"00113023u012Z":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (UTC invalid character in sec)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_UTC_TIME:"0011302359n0Z":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
diff --git a/tests/suites/test_suite_x509parse.function b/tests/suites/test_suite_x509parse.function
index 156a25f..5eec72a 100644
--- a/tests/suites/test_suite_x509parse.function
+++ b/tests/suites/test_suite_x509parse.function
@@ -613,16 +613,14 @@
                     int hour, int min, int sec )
 {
     mbedtls_x509_time time;
-    unsigned char buf[17];
+    unsigned char buf[21];
     unsigned char* start = buf;
     unsigned char* end = buf;
 
     memset( &time, 0x00, sizeof( time ) );
     *end = (unsigned char)tag; end++;
-    if( tag == MBEDTLS_ASN1_UTC_TIME )
-        *end = 13;
-    else
-        *end = 15;
+    *end = strlen( time_str );
+    TEST_ASSERT( *end < 20 );
     end++;
     memcpy( end, time_str, (size_t)*(end - 1) );
     end += *(end - 1);